Letrozole Side Effects

Medically reviewed byEditorial Medical Review, MD, NAMS-CMP

Last reviewed: 5/27/2026 · Verify credentials →

Letrozole side-effect incidence rates below are drawn from FDA prescribing information and clinical trials. Most common effects are gastrointestinal and peak during dose changes.

Common side effects(5)

Incidence rates from clinical trials. Individual experience varies.

Letrozole common side effects with incidence rates
Effect	Incidence	Note
Hot flashes	~14%	Most common; from estrogen suppression
Fatigue	8-13%
Dizziness	~5%
Headache	5-9%
Nausea	~7%

Serious side effects(3)

Less common but require medical attention.

Multiple pregnancy (twins). Lower twin rate than clomiphene, but still elevated vs natural conception
Ovarian hyperstimulation (rare at fertility doses). More associated with injectable gonadotropins than oral letrozole
Bone density loss (long-term, breast-cancer dosing). Not a concern for short 5-day fertility courses

Managing side effects(4)

For ovulation induction it is taken only 5 days early in the cycle — side effects are short-lived
Hot flashes usually resolve once the 5-day course ends
Timed intercourse or monitoring is scheduled around predicted ovulation
Report severe pelvic pain or bloating (possible overstimulation)

Telehealth providers that prescribe Letrozole(4)

Independently reviewed providers offering Letrozole for PCOS ovulation support. Editorial ranking — affiliate links don't affect order.

Allara
90/100
Comprehensive PCOS and hormonal health telehealth. Multidisciplinary care team including endocrinologists, dietitians, and mental health professionals.
Pollie (PCOS Specialist)
85/100
PCOS-focused platform with phenotype-driven treatment matching. Specialist providers only.
Pollie
77/100
PCOS-focused care platform combining clinician access with personalized supplement protocols. Subscription model with medication and supplement bundling.
Felix Health PCOS
77/100
Async PCOS prescribing for acne, hirsutism, and irregular cycles. Affordable monthly plans.

We don't sell Letrozole or any medication. These are editorial reviews of telehealth providers — clicking through may earn us a commission, which does not affect our scoring.

Sources(4)

Was this Letrozole side-effects guide helpful?

Letrozole Side Effects

Medically reviewed byEditorial Medical Review, MD, NAMS-CMP

Last reviewed: 5/27/2026 · Verify credentials →

Letrozole side-effect incidence rates below are drawn from FDA prescribing information and clinical trials. Most common effects are gastrointestinal and peak during dose changes.

Common side effects(5)

Incidence rates from clinical trials. Individual experience varies.

Letrozole common side effects with incidence rates
Effect	Incidence	Note
Hot flashes	~14%	Most common; from estrogen suppression
Fatigue	8-13%
Dizziness	~5%
Headache	5-9%
Nausea	~7%

Serious side effects(3)

Less common but require medical attention.

Multiple pregnancy (twins). Lower twin rate than clomiphene, but still elevated vs natural conception
Ovarian hyperstimulation (rare at fertility doses). More associated with injectable gonadotropins than oral letrozole
Bone density loss (long-term, breast-cancer dosing). Not a concern for short 5-day fertility courses

Managing side effects(4)

For ovulation induction it is taken only 5 days early in the cycle — side effects are short-lived
Hot flashes usually resolve once the 5-day course ends
Timed intercourse or monitoring is scheduled around predicted ovulation
Report severe pelvic pain or bloating (possible overstimulation)

Telehealth providers that prescribe Letrozole(4)

Independently reviewed providers offering Letrozole for PCOS ovulation support. Editorial ranking — affiliate links don't affect order.

Allara
90/100
Comprehensive PCOS and hormonal health telehealth. Multidisciplinary care team including endocrinologists, dietitians, and mental health professionals.
Pollie (PCOS Specialist)
85/100
PCOS-focused platform with phenotype-driven treatment matching. Specialist providers only.
Pollie
77/100
PCOS-focused care platform combining clinician access with personalized supplement protocols. Subscription model with medication and supplement bundling.
Felix Health PCOS
77/100
Async PCOS prescribing for acne, hirsutism, and irregular cycles. Affordable monthly plans.

We don't sell Letrozole or any medication. These are editorial reviews of telehealth providers — clicking through may earn us a commission, which does not affect our scoring.

Was this Letrozole side-effects guide helpful?