Compare Supplements

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

Oral letrozole 2.5 mg tablet (Femara / generic)

300mg standardized extract

With meals · with food

Standardized extract (300–600 mg, 2.5% rosmarinic acid)

• Pregnancy (teratogenic risk) — used to induce ovulation, but stopped once pregnancy occurs
• Premenopausal women for breast-cancer indication without ovarian suppression
• Hypersensitivity to letrozole

• Tamoxifen / other estrogen-modulating agents
• Exogenous estrogen / hormone therapy
• Exogenous testosterone / anabolic steroids

• Epilepsy or seizure disorders (thujone content may lower seizure threshold)
• Pregnancy (may stimulate uterine contractions; avoid therapeutic doses)
• Hormone-sensitive cancers (estrogenic activity; consult oncologist)

• Anticoagulants (warfarin, heparin)
• Antidiabetic drugs (metformin, insulin, sulfonylureas)
• Anticonvulsants (phenytoin, valproate, carbamazepine)