Use of Curcumin to Treat Unfavorable Bleeding Patterns in Contraceptive Implant Users: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Use of Curcumin to Treat Unfavorable Bleeding Patterns in Contraceptive Implant Users (NCT04205929), a randomized phase 4 study. The primary outcome is Total Number of Days Without Bleeding or Spotting.

2. Clinical Question

The trial addressed a specific treatment question about bleeding patterns among contraceptive implant users. The primary outcome focuses on days without either bleeding or spotting during the defined 30-day reference period. A higher mean for this outcome corresponds to more days without bleeding or spotting within that period; it does not by itself describe the timing or sequence of bleeding episodes.

The posted results report means and standard deviations for both groups. The placebo group had a mean of 17.5 days without bleeding or spotting, while the curcumin group had a mean of 16.7 days. The mean difference for curcumin versus placebo was -0.8 days, with an interval from -3.993 to 2.393 days. These are group-level summaries for the trial's stated outcome and timeframe. They do not describe every participant's experience or establish whether any individual participant had a particular bleeding pattern.

The registry record identifies the study as randomized and triple-masked, with placebo and curcumin as the two interventions. It reports enrollment of 58 and primary-outcome group sizes of 28 for placebo and 26 for curcumin. The record does not provide further details about eligibility, the analysis population, or how missing outcome observations were handled. The clinical question can therefore be stated from the intervention descriptions and outcome definition, but the record does not support additional assumptions about participant selection or the conduct of the analysis.

3. Trial Design

The registry record describes a completed, randomized, triple-masked, parallel-group Phase 4 clinical trial sponsored by Oregon Health and Science University. It lists an enrollment of 58. The record gives a start date of 2020-04-15 and a primary completion date of 2022-11-05. The intervention arms were curcumin and placebo.

Participants in the curcumin group were assigned oral curcumin 600 mg once daily for 30 days, beginning after 3 consecutive days of bleeding. Participants in the placebo group were assigned oral placebo once daily for 30 days, with the same stated start condition. The parallel design means the intervention groups are compared with one another over the trial outcome period rather than being described as successive treatment periods for the same participants. The registry record does not report further details about randomization procedures, allocation concealment, the masking of particular roles, or adherence monitoring.

The primary outcome was the total number of days without bleeding or spotting from Day 1 to Day 30, summarized as a mean and standard deviation. The posted outcome summaries list 28 participants in the placebo group and 26 in the curcumin group for this endpoint. Those outcome group sizes should be distinguished from the registry enrollment figure; the record does not explain the relationship between enrollment and the outcome denominators.

Three secondary outcomes are posted: total bleeding/spotting days, total spotting days, and total bleeding days, each over Day 1 to Day 30 and summarized as means and standard deviations. The record lists 6 outcome measures overall, but the additional outcomes are not described in the posted results summarized in these statistics. No reported analysis entries are listed for the primary or secondary outcomes. Details of the original sample-size justification, planned statistical methods, analysis populations, interim analyses, and handling of missing data are not reported in the registry record.

4. Participant Flow and Accounting

The registry reports how participants moved through each stage of the study. All counts below are exactly as posted; missing counts are not inferred from other stages.

Overall Study

5. Baseline Characteristics

The table reproduces the baseline characteristics posted in the registry, which describe the participants analysed at baseline and help show whether the randomized groups were comparable.

6. Primary Endpoint

The registry lists the primary outcome as Total Number of Days Without Bleeding or Spotting, measured over Day 1 to Day 30.

The primary endpoint is the total number of days without bleeding or spotting during the 30-day reference period, from Day 1 to Day 30. It counts days without either form of bleeding-related event. The registry record describes it as a continuous measure and reports a mean and standard deviation for each randomized group.

This outcome is useful for expressing the frequency of days free from bleeding or spotting across the specified period. Unlike an outcome limited to bleeding days or spotting days, it combines days without either event into one summary. In general, continuous outcomes can preserve more gradation than a simple classification into categories, because participants may have different numbers of event-free days. The mean gives a group-level average, while the standard deviation describes how spread out individual values are around that average. These are general interpretations of the statistics, not additional findings about individual participants.

The posted mean was 17.5 days in the placebo group and 16.7 days in the curcumin group. The reported comparison is a mean difference of -0.8 days for curcumin versus placebo. The endpoint summarizes only the defined 30-day window; it does not establish whether bleeding occurred in consecutive or separate episodes, how severe it was, or how participants experienced it. Those details are not reported in the registry record. The registry record also does not report a threshold defining a clinically important difference for this endpoint, so the statistical summaries alone do not establish the importance of a difference to participants.

7. Results Posted in the Registry

• Curcumin Group: mean 16.70 versus 17.50 on control; difference -0.80 (95% CI -3.99 to 2.39), standardized effect d = -0.14; z-test p = 0.623.

8. Secondary Efficacy Endpoints

The registry also posts results for secondary outcomes. For each outcome below, the endpoint type, the test applied to the posted summary statistics, the result and its interpretation are given in turn. Secondary endpoints are usually not adjusted for multiple testing, so they support rather than confirm the primary finding.

Total Number of Bleeding/Spotting Days

• Endpoint type: Continuous: a mean value per participant, compared as a difference in means.
• Test: Unadjusted two-sample z-test for the difference in means, using the posted standard deviations.
• Result:
  • Curcumin Group: mean 13.30 versus 12.50 on control; difference 0.80 (95% CI -2.39 to 3.99), standardized effect d = 0.14; z-test p = 0.623.
• Interpretation:
  • The 95% confidence interval includes no difference, so these data do not show a statistically significant difference between Curcumin Group and the control. The interval gives the range of effects that remain compatible with the data.

Total Number of Spotting Days

• Endpoint type: Continuous: a mean value per participant, compared as a difference in means.
• Test: Unadjusted two-sample z-test for the difference in means, using the posted standard deviations.
• Result:
  • Curcumin Group: mean 6.70 versus 4.90 on control; difference 1.80 (95% CI -0.21 to 3.81), standardized effect d = 0.48; z-test p = 0.080.
• Interpretation:
  • The 95% confidence interval includes no difference, so these data do not show a statistically significant difference between Curcumin Group and the control. The interval gives the range of effects that remain compatible with the data.

Total Number of Bleeding Days

• Endpoint type: Continuous: a mean value per participant, compared as a difference in means.
• Test: Unadjusted two-sample z-test for the difference in means, using the posted standard deviations.
• Result:
  • Curcumin Group: mean 6.60 versus 7.60 on control; difference -1.00 (95% CI -3.52 to 1.52), standardized effect d = -0.21; z-test p = 0.436.
• Interpretation:
  • The 95% confidence interval includes no difference, so these data do not show a statistically significant difference between Curcumin Group and the control. The interval gives the range of effects that remain compatible with the data.

The three posted secondary outcomes describe total bleeding/spotting days, spotting days, and bleeding days during the same Day 1 to Day 30 period. Considered together, their directions are mixed: the curcumin group had higher mean values for total bleeding/spotting days and spotting days, but a lower mean for bleeding days. The primary outcome, days without bleeding or spotting, is another view of the same general pattern over that period.

These measures are related rather than independent. Total bleeding/spotting days combines two types of days, while the separate spotting and bleeding outcomes distinguish them. Consequently, a difference in one component can accompany a different direction in another, and multiple related outcomes do not automatically provide multiple independent confirmations. Their shared timeframe and subject matter make it important to consider the set of results as a whole rather than selecting one result in isolation.

The secondary outcomes do not overturn the primary result or provide a definitive explanation for it. They add descriptive context about which kinds of days contributed to the broader bleeding pattern, but the registry record lists no reported analyses for them. The posted comparisons are unadjusted. When several outcomes are examined, the chance of seeing an apparently notable result among them can increase; multiplicity procedures are one general way to address that issue. Whether any procedure was planned or used is not reported in the registry record.

Accordingly, the secondary summaries carry less weight than a prespecified primary analysis would carry, particularly because the original analysis plan and any multiplicity strategy are not reported. They are useful for describing the observed pattern, but they should not be treated as confirmatory evidence or as proof of a specific mechanism. The record does not provide a stated hierarchy for interpreting secondary endpoints.

Secondary outcomes registered for this trial, for reference (only those above were recalculated):

• Total Number of Bleeding/Spotting Days
• Total Number of Spotting Days
• Total Number of Bleeding Days

9. Statistical Interpretation

10. Statistical Methods Explained

The primary outcome is continuous: it is a count of days, summarized in the registry record as a mean and standard deviation. For this kind of summary, the mean describes the average number of days for a group. The standard deviation describes how much participant-level values vary around that group average. It is not the uncertainty of the mean difference; that uncertainty is reflected by the interval for the comparison.

The posted primary group means are 17.5 days for placebo and 16.7 days for curcumin. The comparison is expressed as a mean difference for curcumin versus placebo, estimated at -0.8 days. The sign depends on that ordering: a negative estimate indicates a lower mean in the curcumin group, while a positive estimate would indicate a higher mean in that group. The comparison uses the posted group summaries and is an unadjusted recalculation, rather than a reported sponsor analysis.

An interval around an estimated difference conveys uncertainty about the size and direction of the difference. In general, an interval is more informative than a point estimate alone because it displays a range of values compatible with the data and the method used to calculate it. The primary interval extends from -3.993 to 2.393 days. It covers zero, which corresponds to no difference in group means, as well as values in either direction. The registry record does not state the interval's confidence level or give a sponsor-reported interval, so the interpretation should stay with the posted range rather than assume additional details about its construction.

The unadjusted p-value for the primary comparison is 0.623. In general, a p-value describes how unusual data at least as incompatible with a specified null model would be if that model and the test assumptions were true. It is not the probability that the null hypothesis is true, nor the probability that a treatment effect is real. It also does not measure the size or clinical importance of an effect. The registry record does not report the original statistical test or adjustment plan, so the p-value is best described as the unadjusted value associated with the recalculated comparison.

Why do standard deviations and standard errors differ?

Standard deviations describe the spread of participant values within a group. Standard errors describe the statistical uncertainty of an estimate, such as a group mean, under a calculation method. These quantities answer different questions and should not be substituted for one another. The posted comparison information includes group-level standard errors, but they do not replace the reported standard deviations when describing variation among participants.

What does over-dispersion mean in general?

Over-dispersion occurs when observed variability is larger than a statistical model assumes. This can make model-based uncertainty too small if the extra variability is ignored. It is a general issue in some count-data analyses; the registry record does not report an over-dispersion assessment or identify a count model for these outcomes. The primary result is reported as a mean and standard deviation, and no model details are reported.

What limits interpretation of the recalculation?

A summary-based comparison does not reveal participant-level distributions, possible influential observations, or patterns in missing data. It also cannot reproduce adjustments or modeling choices that might have been used in an unreported sponsor analysis. No discrepancy is flagged in the posted record, but the absence of a reported analysis means that the calculation should not be mistaken for a complete account of the trial's original statistical plan. If a discrepancy between a recalculation and a sponsor analysis were identified, the sponsor's own analysis would take precedence; no such discrepancy is flagged.

The primary outcome and secondary outcomes are measured over the same 30-day timeframe and concern overlapping aspects of bleeding patterns. In general, related outcomes can be correlated, so treating each result as an independent test may overstate the amount of distinct evidence. The registry record does not report whether the investigators adjusted for multiple comparisons or designated an order for secondary analyses. The secondary p-values are unadjusted, and should be interpreted with that limitation in mind.

The record also does not report whether the analysis followed intention-to-treat principles, whether participants were excluded from any outcome analysis, how missing observations were handled, or whether assumptions for the comparisons were checked. These are important details for understanding the estimand and the reliability of the uncertainty calculations. Without them, interpretation should remain anchored to the posted summaries and avoid claims about methods that are not described in the registry record.

11. Confidence Intervals and Precision

The primary estimate is a mean difference of -0.8 days for curcumin versus placebo, with an interval from -3.993 to 2.393 days. The estimate is therefore not very precise about the direction or magnitude of the difference: the interval includes zero and extends to values favoring either group. The posted group means, 17.5 days for placebo and 16.7 days for curcumin, are point summaries; the interval gives additional information about uncertainty in their comparison.

In general, an interval is a range generated by a statistical procedure to express uncertainty around an estimate. A narrower interval indicates greater precision than a wider interval when the same kind of interval and method are being compared. An interval spanning zero does not prove that the groups are identical. It indicates that the estimate does not precisely distinguish the direction of the mean difference using that interval. The confidence level is not reported in the registry record, so no confidence level should be inferred from the interval alone.

The posted standard deviations also show variation among participant measurements: 4.8 days for placebo and 6.9 days for curcumin. These describe the spread of individual values, not the precision of the treatment comparison. The outcome group sizes were 28 and 26, respectively, and the registry record does not explain the difference between those numbers and the enrollment of 58.

Precision is distinct from clinical importance. The registry record does not report a threshold for a meaningful difference in days without bleeding or spotting, so the interval cannot be judged against such a threshold from the record alone. The uncertainty should be considered alongside the endpoint definition, related secondary outcomes, and the unreported analysis and missing-data details. The result is best read as an estimate with a broad range of plausible values, not as proof of a precise effect or of no effect.

12. Planning a Similar Trial: Sample Size

This is a planning illustration, not a re-evaluation of the original trial. It asks: if a new study wanted to detect a difference like the one observed, or a smaller one, how large would it need to be? It is deliberately not “observed power” of the finished trial, which is not a meaningful quantity.

The planning figures are participants per arm, not total events. They are illustrations based on the observed effect and use a two-sided significance level of 0.05, equal allocation between the two arms, and a normal approximation. The effect targeted in each planning scenario is the stated fraction of the observed effect. These assumptions describe the planning illustration; the trial's own original sample-size assumptions and justification are not reported in the registry record.

The 80% power column represents the number of participants per arm that the illustration estimates would be needed for an 80% chance of detecting the specified effect under those assumptions. The 90% power column gives the corresponding planning figure for a 90% chance. Power is a property of a planned study under specified assumptions; it is not the probability that a finding is true, and it does not state what happened in this trial.

For the primary endpoint, the planning entries are 855 participants per arm for 80% power and 1,145 for 90% power when planning for 100% of the observed effect. For 75% of the observed effect, the figures are 1,520 and 2,035 participants per arm. For 50% of the observed effect, they are 3,420 and 4,578 participants per arm. Smaller effects need more participants to detect under the same planning assumptions, which is why the required figures increase as the targeted fraction decreases. These are planning illustrations, not the trial's observed enrollment requirements or a reconstruction of its original design. They are not observed power.

The registry record does not report the assumptions used to select the original enrollment target, nor does it report an original power calculation. The illustration is tied to the observed effect, which is uncertain, and should not be read as a recommended sample size without considering the scientific question, the desired precision, and the design assumptions appropriate to a future study.

13. How the Sample Size Is Derived

Power is the probability that a study of a given size rejects the null hypothesis when a specific true effect exists. It depends on four things: the effect to detect, the variability of the outcome, the significance level (here a two-sided α of 0.05, so z_1−α/2 = 1.960) and the desired power (z_1−β = 0.842 for 80% and 1.282 for 90%).

Formula

n is the number of participants in each arm, Δ is the difference in means to detect and σ is the common standard deviation.

Worked calculation for this trial

1. Observed difference Δ = -0.800; pooled standard deviation σ = 5.904.
2. n = 2 × (1.96 + 0.842)² × 5.904² / -0.800² = 854.9, rounded up to 855 participants per arm for 80% power.

The smaller-effect rows in the table above repeat the same calculation with the effect multiplied by 0.75 and 0.5 (for ratios, applied to the logarithm of the ratio).

R code

alpha <- 0.05
z_a   <- qnorm(1 - alpha / 2)          # two-sided
delta <- -0.800000000000001                      # observed difference in means
sigma <- 5.90360059624633                     # pooled standard deviation
n_per_arm <- function(power, frac = 1) {
  ceiling(round(2 * (z_a + qnorm(power))^2 * sigma^2 / (delta * frac)^2, 6))
}
for (f in c(1, 0.75, 0.5))
  cat(sprintf("%3.0f%% of observed effect: n per arm = %s (80%% power), %s (90%% power)\n", 100 * f,
              format(n_per_arm(0.80, f), big.mark = ","), format(n_per_arm(0.90, f), big.mark = ",")))

# Check against R's built-in function (t-based, so very slightly larger)
cat("power.t.test:", round(power.t.test(delta = delta, sd = sigma, power = 0.80)$n, 1), "\n")

# Simulation: exact two-sample t-test using simulated means and variances
set.seed(4205929)
n    <- n_per_arm(0.80)
reps <- 20000
m_diff <- rnorm(reps, delta, sigma * sqrt(2 / n))             # difference in sample means
s2     <- sigma^2 * rchisq(reps, 2 * (n - 1)) / (2 * (n - 1))   # pooled sample variance
tstat  <- m_diff / sqrt(s2 * 2 / n)
cat(sprintf("Simulated power at n = %s per arm: %.3f (%d replicates)\n", format(n, big.mark = ","), mean(abs(tstat) > qt(0.975, 2 * (n - 1))), reps))

Output from running the code

100% of observed effect: n per arm = 855 (80% power), 1,145 (90% power)
 75% of observed effect: n per arm = 1,520 (80% power), 2,035 (90% power)
 50% of observed effect: n per arm = 3,420 (80% power), 4,578 (90% power)
power.t.test: 855.8 
Simulated power at n = 855 per arm: 0.799 (20000 replicates)

The simulation draws many sets of group means and variances at the planned sample size and counts how often the two-sample t-test rejects the null. It should land close to the target power; at very small required sample sizes it can fall below it, because the normal approximation is rough there.

14. Multiplicity, Missing Data and Analysis Populations

The registry record identifies a primary endpoint and posts three secondary endpoints, but it does not report a statistical analysis plan describing how these outcomes were to be tested or interpreted. The secondary comparison p-values are unadjusted. Whether the investigators planned a multiplicity correction, designated a hierarchy among secondary outcomes, or treated them as exploratory is not reported in the registry record.

Multiplicity matters in general because repeated testing across multiple outcomes can make at least one apparently notable result more likely even when no underlying difference exists. Adjustment methods can control this issue, but they may also affect precision and interpretation. Since no adjustment strategy is reported, the secondary comparisons should be read as unadjusted summaries rather than as a set of confirmatory tests. The primary endpoint's unadjusted comparison should also not be assumed to reflect any broader adjustment for other outcomes.

The registry record does not report how missing outcome data were handled, whether all randomized participants were included in each analysis, or which analysis population was used. It also does not explain the relationship between the enrollment of 58 and the primary outcome group sizes of 28 and 26. These details matter because excluding participants or handling missing values differently can affect the group estimates and their uncertainty. No missing-data method, sensitivity analysis, or imputation procedure is reported.

The record does not report whether the analyses followed an intention-to-treat approach, a per-protocol approach, or another population definition. It also does not report interim analyses, stopping rules, covariate adjustment, baseline adjustment, or the original test used for each outcome. These omissions do not establish that such procedures were absent; they mean their use and details are not reported in the registry record. Interpretation should therefore distinguish the posted outcome summaries and recalculated unadjusted comparisons from any unreported sponsor analysis or protocol-defined plan.

15. Safety Results

The registry reports serious adverse events as affected participants divided by participants at risk.

Deaths

Other (non-serious) adverse events

Participants with at least one non-serious event at or above the registry's 0% reporting threshold.

Most frequent non-serious adverse event terms

The safety figures use a separate denominator from the primary outcome summaries: 29 participants were listed at risk in each group for serious and other adverse events. The registry record reports zero serious adverse events in the placebo group and zero in the curcumin group. It also reports one participant affected by an other adverse event in the placebo group and two in the curcumin group. Deaths were reported as zero in both groups.

These counts are descriptive and should be read in light of the number at risk and the limited information reported. The record does not provide serious adverse event terms, since no serious terms are listed, or further detail about the other adverse events, their timing, severity, or relationship to the intervention. The safety counts do not establish that an event could not occur, and they do not replace a complete assessment of adverse-event reporting. The registry record does not explain why the safety denominator differs from the primary-outcome group sizes.

16. What the Result Does, and Does Not, Mean

The posted primary result is an estimated mean difference of -0.8 days without bleeding or spotting for curcumin versus placebo over Day 1 to Day 30. The interval, from -3.993 to 2.393 days, includes zero and spans possible differences in either direction. The unadjusted p-value is 0.623. Together, these summaries describe an uncertain group comparison; they do not establish a precise difference between the interventions.

That interpretation is narrower than saying that the interventions are equivalent or that there is no difference. Demonstrating equivalence or ruling out differences large enough to matter would require an appropriate design and a prespecified margin or threshold. Such a margin is not reported in the registry record. Likewise, a non-small p-value is not proof that the null hypothesis is true, and it does not indicate the probability that the observed result arose by chance.

The primary endpoint captures the number of days without bleeding or spotting in one 30-day period. It does not describe the timing, duration, severity, or personal importance of episodes. The secondary outcomes provide related summaries of bleeding and spotting days, with mixed directions, but their unadjusted status and the lack of a reported multiplicity plan limit how strongly they can be interpreted.

The registry record also leaves important design and analysis details unreported, including the original sample-size justification, analysis populations, and handling of missing data. These omissions limit evaluation of the precision and representativeness of the estimates. The posted results should therefore be understood as trial summaries for the stated groups and timeframe, not as a prediction for every implant user or a treatment recommendation. They do not establish a definitive effect, the absence of an effect, or the clinical importance of a difference.

17. Why This Trial Matters Statistically

This trial raises several useful statistical questions for clinical researchers. First, it illustrates the distinction between a group mean and the experience of individual participants. A mean number of days without bleeding or spotting can summarize a group, while the standard deviation describes variation around that mean. Neither statistic, by itself, shows the sequence or severity of individual bleeding patterns.

Second, the primary estimate needs to be interpreted with its interval rather than as a standalone point value. The estimate is -0.8 days, while its interval ranges from -3.993 to 2.393 days. That spread makes the uncertainty and the range of possible directions visible. Statistical interpretation is not simply a choice between a positive or negative result; it also considers how precisely the effect has been estimated and whether a clinically meaningful threshold is defined.

Third, the secondary measures are related. Total bleeding/spotting days, spotting days, bleeding days, and days without bleeding or spotting each frame the same 30-day pattern in different ways. Considering how outcomes overlap helps prevent overinterpreting a single unadjusted comparison. The record does not report a multiplicity plan, which is an important limitation when several outcomes are posted.

Finally, the registry record demonstrates why transparency about the analysis population, missing data, and original sample-size rationale matters. Enrollment and outcome denominators are not the same figures in the record, and their relationship is not explained. Without details of the original analysis plan, readers can describe the posted estimates but cannot fully assess how they were produced or how they relate to the intended design. These distinctions are central to careful evidence interpretation.

18. Limitations

• The posted summary statistics are the only data these results rest on; patient-level data, full protocols and statistical analysis plans are not available.
• Recalculated results are simple, unadjusted calculations from posted summaries. They do not replace the sponsor's prespecified analysis.

Several trial-specific limitations follow from what the registry record reports and leaves unreported. The primary outcome is restricted to a 30-day period, so it does not describe bleeding patterns outside that window. It is a count of days without bleeding or spotting and does not provide detail on episode timing, severity, or participant-reported burden. The record does not report a threshold for a meaningful difference on this measure.

The posted primary outcome group sizes are 28 for placebo and 26 for curcumin, while registry enrollment is 58. The record does not explain the difference or state whether the same participants contributed to each secondary outcome. It also does not report how missing observations were handled, which participants were included in the analyses, or whether the analysis followed an intention-to-treat principle. Those omissions make it difficult to assess the potential influence of missingness or exclusions.

The record lists three secondary outcomes, but no reported analysis entries are listed, and the secondary comparison p-values are unadjusted. It does not report whether the analyses were prespecified, whether any multiplicity method was used, or how secondary results were intended to inform interpretation. The original statistical methods and sample-size justification are also not reported, so the recalculated comparisons cannot be assumed to reproduce the trial's planned analysis.

Safety information is limited to event counts and numbers at risk; details of other adverse events are not reported. The registry record also does not describe adherence, randomization procedures, allocation concealment, or masking procedures beyond identifying the trial as triple-masked. These are limits on what can be concluded from the record, not evidence that a particular procedure was or was not followed.

19. Related Tutorials

20. Related Statistical Calculators

21. Sources

• ClinicalTrials.gov: Use of Curcumin to Treat Unfavorable Bleeding Patterns in Contraceptive Implant Users — NCT04205929.
• Registry record last updated 2024-07-03; status last verified 2024-01.
• Results first posted 2024-07-03.
• Data retrieved from ClinicalTrials.gov on 2026-11-09.
• Group sizes, means, event counts and sponsor-reported p-values are reproduced as posted. Effect estimates, confidence intervals and p-values not attributed to the sponsor are independently calculated from the posted summary statistics.

22. Record Summary

The registry record describes a completed, randomized, triple-masked, parallel-group Phase 4 trial of oral curcumin versus oral placebo for unfavorable bleeding patterns in contraceptive implant users. Both interventions were taken once daily for 30 days after 3 consecutive days of bleeding. The primary outcome was the mean number of days without bleeding or spotting from Day 1 to Day 30.

The posted primary means were 17.5 days for placebo and 16.7 days for curcumin. The unadjusted mean difference for curcumin versus placebo was -0.8 days, with an interval from -3.993 to 2.393 days and an unadjusted p-value of 0.623. The record also posts three related secondary outcomes and limited adverse-event counts. Original analysis details, the sample-size justification, analysis populations, and missing-data methods are not reported in the registry record.