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Head-to-head evidence comparison — which supplement is right for you?
Folic Acid vs Letrozole: Folic Acid has the stronger overall evidence (8 vs 5/10); the best pick depends on your goals. Take the 60-second quiz for a pick tailored to your goals.
Folic Acid wins 2 of 3 categories. Both are solid choices — the best pick depends on your specific goals.
Verdict
Mostly mechanism / observational
Verdict
Mostly mechanism / observational
Top outcomes
400 mcg/day for anyone planning or capable of pregnancy (USPSTF: 400-800 mcg); adult RDA 400 mcg DFE/day, 600 mcg DFE in pregnancy, 500 mcg DFE in lactation (IOM)
any
Folic acid (pteroylmonoglutamic acid)
Indication-specific and clinician-directed. Ovulation induction: 2.5-7.5 mg once daily for 5 days early in the cycle (typically days 3-7). Breast cancer: 2.5 mg once daily continuously. Off-label male use mirrors 2.5 mg once to a few times weekly (NOT daily) titrated to testosterone/estradiol — a prescription drug, not an approved supplement regimen.
any
Oral letrozole 2.5 mg tablet (Femara / generic)
Periconceptional
Weeks
Weeks to months
Per cycle (days 3-7 dosing)
Weeks to months
Months to years
Months to years
Prevention of the first occurrence of neural-tube defects by periconceptional vitamin supplementation.
N Engl J Med (1992) · Rct
Randomised trial of periconceptional vitamin supplementation for prevention of a FIRST neural tube defect (PubMed publication types: Randomized Controlled Trial, Clinical Trial)
Prevention of neural tube defects: results of the Medical Research Council Vitamin Study. MRC Vitamin Study Research Group.
Lancet (1991) · Rct
Randomised, multicentre trial of periconceptional folic acid for prevention of RECURRENT neural tube defects (PubMed publication types: Randomized Controlled Trial, Multicenter Study, Comparative Study)
Effects and safety of periconceptional oral folate supplementation for preventing birth defects.
Cochrane Database Syst Rev (2015) · Meta analysis
Cochrane Database of Systematic Reviews CD007950, third edition (PubMed publication types: Meta-Analysis, Systematic Review)
Letrozole versus clomiphene for infertility in the polycystic ovary syndrome.
The New England journal of medicine (2014) · Rct · n=750
Double-blind multicenter RCT of 750 women with PCOS randomized to letrozole or clomiphene for up to five cycles, primary outcome live birth
Aromatase inhibitors (letrozole) for ovulation induction in infertile women with polycystic ovary syndrome.
Cochrane Database of Systematic Reviews (2022) · Meta analysis
Cochrane systematic review of 41 RCTs (6522 women); letrozole was used in all trials
Somatic and psychological effects of low-dose aromatase inhibition in men with obesity-related hypogonadotropic hypotestosteronemia.
European journal of endocrinology (2013) · Rct · n=42
Double-blind, placebo-controlled 6-month RCT of letrozole in 42 obese men (BMI >35) with low testosterone, dose-titrated to a target testosterone
Folic Acid has a higher evidence score (8/10 vs 5/10) and wins in 2 of 3 categories.
No known interactions between Folic Acid and Letrozole have been documented in our database. However, always consult a healthcare provider before combining supplements.
The right pick depends on your goals. Answer a few quick questions for a personalised recommendation — or dig into the full evidence on each.