Loading…
We use essential cookies (authentication, your saved goals/stack) by default. With your permission we’ll also enable privacy-respecting analytics (Vercel Web Analytics, anonymous load-time metrics) and error-replay diagnostics (Sentry — DOM snapshots only when an error fires) so we can fix bugs faster. Learn more about cookies
Head-to-head evidence comparison — which supplement is right for you?
L. crispatus CTV-05 vs Letrozole: L. crispatus CTV-05 has the stronger overall evidence (6 vs 5/10); the best pick depends on your goals. Take the 60-second quiz for a pick tailored to your goals.
L. crispatus CTV-05 wins 2 of 3 categories. Both are solid choices — the best pick depends on your specific goals.
Verdict
Mostly mechanism / observational
Top outcomes
Verdict
Too few graded studies
Top outcomes
Shared outcomes (1)
Outcomes where both L. crispatus CTV-05 and Letrozole have evidence — compare verdict strength side-by-side.
VAGINAL USE ONLY, by applicator: 2 x 10^9 CFU per dose. The phase 2b regimen was one dose daily for 5 days in week 1, then twice weekly for a further 10 weeks — always started after a completed course of vaginal metronidazole gel.
Any time of day
Vaginal applicator delivering L. crispatus CTV-05
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 time of day
Oral letrozole 2.5 mg tablet (Femara / generic)
11-week dosing course, measured at 12 weeks
n/a
Days 10-28
Persisting to 24 weeks
Per cycle (days 3-7 dosing)
Weeks to months
Months to years
Months to years
Randomized Trial of Lactin-V to Prevent Recurrence of Bacterial Vaginosis.
N Engl J Med (2020) · Rct · n=228
Recurrence of bacterial vaginosis by week 12: 30% (46/152) with Lactin-V vs 45% (34/76) with placebo; risk ratio 0.66 (95% CI 0.44-0.87), P=0.01
Response to Antibiotic Treatment of Bacterial Vaginosis Predicts the Effectiveness of LACTIN-V (Lactobacillus crispatus CTV-05) in the Prevention of Recurrent Disease.
Sex Transm Dis (2024) · Observational
This is a POST HOC analysis of the already-completed phase 2b LACTIN-V trial, not a new trial
Sustained effect of LACTIN-V (Lactobacillus crispatus CTV-05) on genital immunology following standard bacterial vaginosis treatment: results from a randomised, placebo-controlled trial.
Lancet Microbe (2022) · Rct · n=66
Vaginal IL-1α was significantly lower with LACTIN-V (β 0.310, SE 0.149; p=0.042)
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 · n=6522
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
L. crispatus CTV-05 has a higher evidence score (6/10 vs 5/10) and wins in 2 of 3 categories.
No documented interaction was found in the data searched. This does not establish that this exact combination is safe.
The right pick depends on your goals. Answer a few quick questions for a personalised recommendation — or dig into the full evidence on each.