Can progesterone cause scalp hair loss and hirsutism (Hypertrichosis)?

Can Progesterone Cause Scalp Hair Loss and Hirsutism?

Progesterone itself does not directly cause hirsutism or hypertrichosis, but progestogen-only regimens may worsen certain conditions in some patients and should be used with caution. 1

Scalp Hair Loss

Progesterone is not a recognized cause of scalp hair loss. In fact, the evidence suggests the opposite relationship:

• Low progesterone levels (indicating anovulation) are associated with conditions like polycystic ovary syndrome (PCOS), which itself can cause hirsutism and potentially affect hair patterns 1
• Endocrine-induced alopecia (such as from aromatase inhibitors in cancer treatment) is characterized by hair loss primarily on the crown and frontal/bitemporal hairline, but this is not related to progesterone therapy 1
• The FDA label for progesterone capsules lists "hair loss" as a less serious but common side effect, though this appears in the context of general adverse events rather than a well-established causal relationship 2

Hirsutism and Hypertrichosis

Progestogen-only regimens carry anecdotal concern for worsening hidradenitis suppurativa and potentially other androgen-sensitive conditions, and should be discontinued if disease worsens. 1

Key Distinctions:

• Hirsutism (androgen-dependent hair growth in female-pattern areas) is primarily driven by androgens, not progesterone 3, 4
• Hypertrichosis (generalized increased hair growth in non-androgen-dependent areas) has iatrogenic causes including minoxidil, cyclosporine, and glucocorticosteroids—but not progesterone 3

Evidence Regarding Progestogens:

• Some progestogens used in contraceptives have androgenic properties that can worsen hirsutism, but this depends on the specific progestogen type 5, 6
• Desogestrel combined with ethinyl estradiol actually reduced androgen-dependent hair growth in hirsute women, demonstrating that non-androgenic progestogens do not cause hirsutism 5
• Medroxyprogesterone acetate (a specific progestogen) has been used successfully to treat hirsutism by suppressing testosterone levels, with 23 of 24 patients showing improvement 7

Clinical Context:

• Natural micronized progesterone is recommended as first-choice progestin in hormone replacement therapy due to its favorable safety profile 1
• Progesterone is prescribed in gender-affirming care for its anecdotal effect on breast development, not for hair-related effects 1
• Anti-androgenic progestogens (like cyproterone acetate) combined with ethinyl estradiol are actually treatments for hirsutism, reducing hirsutism scores significantly 6

Clinical Recommendations:

If a patient on progesterone develops new hair loss or hirsutism:

• Evaluate for underlying hyperandrogenic conditions (PCOS, adrenal disorders, ovarian tumors) with serum testosterone, DHEAS, and 17-OH-progesterone 1, 4
• Consider whether the patient is on a progestogen with androgenic properties rather than natural progesterone 5
• Rule out other causes: thyroid dysfunction (TSH, free T4), iron deficiency (ferritin), vitamin D, and zinc levels 1
• If using progestogen-only regimens and symptoms worsen, discontinue and reassess 1

The relationship between progesterone and hair changes is not one of direct causation but rather involves complex hormonal interactions, with the specific type of progestogen and underlying endocrine status being critical factors. 1, 6