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Head-to-head evidence comparison — which supplement is right for you?
Vitamin D3 wins 2 of 3 categories. Both are solid choices — the best pick depends on your specific goals.
Verdict
Likely helps
4 of 4 studies with measurable effects showed benefit.
Top outcomes
Verdict
Probably helps
18 of 30 studies with measurable effects showed benefit.
Top outcomes
250-750mg daily (standardized to 45-60% saponins)
With meals, Morning or divided doses
Extract standardized to 45-60% saponins (protodioscin)
2000-4000 IU daily
Morning with breakfast
D3 (cholecalciferol) softgel or liquid
2-4 weeks
4-8 weeks
N/A
4-8 weeks
4-8 weeks
2-4 weeks
4-8 weeks
Effects of Tribulus (Tribulus terrestris L.) Supplementation on Erectile Dysfunction and Testosterone Levels in Men-A Systematic Review of Clinical Trials
Nutrients (2025) · Systematic review · n=172
The Jadad score revealed low methodological quality for 50% of the studies.
Dietary Supplements for Erectile Dysfunction: Analysis of Marketed Products, Systematic Review, Meta-Analysis and Rational Use
Nutrients (2023) · Meta analysis
Based on the scoring system, 2 (8%) supplements matched with the cluster of higher expected efficacy, 3 (12%) with the lower efficacy cluster and 20 (80%) matched with the criterion of no expected efficacy.
Beneficial effects of natural products on female sexual dysfunction: A systematic review and meta-analysis
Phytomedicine : international journal of phytotherapy and phytopharmacology (2021) · Meta analysis · n=536
Tribulus terrestris showed a significant positive effect in improving overall female sexual function (SMD = 1.12, 95% CI = 0.46 - 1.79, p = 0.001) compared to placebo.
Vitamin D supplementation vs. placebo and incident type 2 diabetes in an ancillary study of the randomized Vitamin D and Omega-3 Trial
Nature communications (2025) · Meta analysis · n=5205
Mean body mass index (BMI) was 27.5 kg/m2 (SD = 5.3), with 51% female and 17% Black race/ethnicity.
Vitamin D Supplementation for Patients with Dysmenorrhoea: A Meta-Analysis with Trial Sequential Analysis of Randomised Controlled Trials
Nutrients (2024) · Meta analysis · n=687
TSA revealed that the current RCTs provide sufficient information.
Vitamin D and respiratory tract infections
BMJ (2017) · Meta analysis · n=11321
12% reduction in respiratory infections overall
Based on systematic review showing improvement in 3 of 5 studies at 400-750mg doses. Studies had low methodological quality (50% low Jadad scores). Effects primarily in men with existing ED.
Meta-analysis showed 12% overall reduction in respiratory infections, with greater benefits in severely deficient individuals. Daily dosing more effective than bolus. Conservative estimate assumes most users not severely deficient.
AI-estimated from published studies. Interpret as directional guidance.
Vitamin D3 has a higher evidence score (7.5/10 vs 5.5/10) and wins in 2 of 3 categories.
For menopause support, Vitamin D3 has a higher relevance score (90 vs 72).
No known interactions between Tribulus and Vitamin D3 have been documented in our database. However, always consult a healthcare provider before combining supplements.