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Head-to-head evidence comparison — which supplement is right for you?
Tretinoin (Retin-A) and Vitex are closely matched across evidence, studies, and safety.
Verdict
Mostly mechanism / observational
Top outcomes
Verdict
Likely helps
12 of 13 studies with measurable effects showed benefit.
Top outcomes
Prescription topical: a pea-sized amount of 0.025%-0.1% cream or gel applied to clean, dry skin once nightly. Start low-strength and every-other-night to build tolerance. A prescription drug used under clinician direction — not a supplement regimen.
before-bed
Topical cream or gel, 0.025%-0.1% (prescription)
20-40mg extract (standardized to 0.5% agnuside)
Morning, Consistently at same time daily
Standardized extract (0.5% agnuside or 0.6% aucubin)
12-24 weeks
12-24 weeks
Months
8-12 weeks
1-3 cycles
2-3 cycles
1-2 cycles
Topical tretinoin improves photoaged skin. A double-blind vehicle-controlled study.
JAMA (1988) · Rct
Randomized, double-blind, vehicle-controlled trial of topical tretinoin for photoaged forearm and facial skin
Tretinoin emollient cream: a new therapy for photodamaged skin.
J Am Acad Dermatol (1992) · Rct
Multicenter double-blind vehicle-controlled trial of tretinoin emollient cream for photodamaged skin
Long-term treatment of photoaged human skin with topical retinoic acid improves epidermal cell atypia and thickens the collagen band in papillary dermis.
J Am Acad Dermatol (2005) · Open label
Long-term topical retinoic acid on photoaged human skin assessed histologically
Vitex agnus-castus in premenstrual syndrome: A meta-analysis of double-blind randomised controlled trials
Complementary Therapies in Medicine (2019) · Meta analysis · n=1878
Vitex significantly reduced overall PMS symptom scores vs placebo
Herbal medicine for depression and anxiety: A systematic review with assessment of potential psycho-oncologic relevance
Phytotherapy research : PTR (2018) · Systematic review
Overall, 45% of studies reported positive findings with fewer adverse effects compared with conventional medications.
A Critical Approach to Evaluating Clinical Efficacy, Adverse Events and Drug Interactions of Herbal Remedies
Phytotherapy research : PTR (2016) · Review
A critical evaluation of the clinical data regarding the adverse effects has shown that herbal remedies are generally better tolerated than synthetic medications.
Based on meta-analysis of RCTs showing large effect size. Most effective for irritability, mood swings, and breast tenderness. Standardized extracts (Ze 440, BNO 1095) had strongest evidence. High heterogeneity noted between studies.
AI-estimated from published studies. Interpret as directional guidance.
Both Tretinoin (Retin-A) and Vitex are closely matched — the best choice depends on your specific health goals.
No known interactions between Tretinoin (Retin-A) and Vitex have been documented in our database. However, always consult a healthcare provider before combining supplements.