Letrozole

Other names: Femara

The FAA's guidance for letrozole depends on what it is taken for. Each use is below, with its own FAA source and date.

Breast cancer
Polycystic ovarian syndrome (PCOS)

Taken for breast cancer

FAA guidance

Acceptable with conditions.

Examiner

CACI: the examiner can issue when the condition's worksheet criteria are met. Applicants for first- or second-class must provide the worksheet's information annually; applicants for third-class with each required exam

Source: FAA, CACI – Breast Cancer Worksheet. FAA date 27 April 2022. Checked by Crosscheck 14 October 2026

For breast cancer, the FAA's CACI – Breast Cancer Worksheet lists the aromatase inhibitors anastrozole (Arimidex), letrozole (Femara) and exemestane (Aromasin) among its approved medications, when the one used is being well tolerated with no side effects.

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The worksheet applies when the pathology showed carcinoma in situ (Tis), stage 0, ductal or lobular carcinoma in situ, or Paget disease of the breast, with all its other criteria, and the examiner must note in Block 60 one of its statements, which include CACI qualified and not CACI qualified.

Show the FAA's wordsThe official FAA wording: one passage, each with its document and dateOpen

FAA, CACI – Breast Cancer Worksheet · FAA date 27 April 2022

The pathology showed:
Carcinoma in Situ (Tis), Stage 0;
Ductal Carcinoma in Situ (DCIS);
Lobular Carcinoma in Situ (LCIS);
Paget disease of the breast (Tis)
Current medication(s):
Approved medications include:
tamoxifen (Nolvadex);
Aromatase inhibitors: anastrozole (Arimidex), letrozole (Femara), or exemestane (Aromasin)
An approved medication that is being well tolerated with no side effects
AME MUST NOTE in Block 60 one of the following:
CACI qualified breast cancer (Documents do not need to be submitted to the FAA.)
NOT CACI qualified breast cancer.

Sources and datesOne FAA document, with the FAA's date and when Crosscheck checked itOpen

CACI – Breast Cancer Worksheet
FAA date 27 April 2022 · Checked by Crosscheck 14 October 2026 · PDF

Taken for polycystic ovarian syndrome (PCOS)

FAA guidance

Acceptable with conditions.

Examiner

FAA label

ACCEPTABLE

Source: FAA, CACI – PCOS Worksheet. FAA date 25 March 2026. Checked by Crosscheck 14 October 2026

For polycystic ovarian syndrome (PCOS), the FAA's CACI worksheet lists letrozole among its acceptable medications, which may be used in combination; the others are anti-androgens (for example finasteride and dutasteride), metformin, oral contraceptives and spironolactone (with a 7-day wait).

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The worksheet applies with all its other criteria, and the examiner must note in Block 60 one of its statements, which include CACI qualified, and not CACI qualified and deferred.

Show the FAA's wordsThe official FAA wording: one passage, each with its document and dateOpen

FAA, CACI – PCOS Worksheet · FAA date 25 March 2026

Treated with the acceptable medication(s) listed:
(May be used in combination)
Indicate which medication(s) used:
anti-androgen (e.g., finasteride, dutasteride)
letrozole
metformin
oral contraceptive
spironolactone (7-day wait)
AME MUST NOTE in Block 60 one of the following:
CACI qualified Polycystic Ovary Syndrome [PCOS].
NOT CACI qualified Polycystic Ovary Syndrome [PCOS]. I have deferred.

Sources and datesOne FAA document, with the FAA's date and when Crosscheck checked itOpen

CACI – PCOS Worksheet
FAA date 25 March 2026 · Checked by Crosscheck 14 October 2026 · PDF

Taking it for something else? The entries here do not cover that use. The FAA may address it in the guidance for your condition. Ask your examiner.

Letrozole

Taken for breast cancer

Taken for polycystic ovarian syndrome (PCOS)

See also