# 21 - 406 Hirsutism

### 406 Hirsutism

as appropriate. Neuromuscular and psychosomatic etiologies should 
also be considered.
Some women experience discomfort at the time of ovulation (mit­
telschmerz or ovulation pain). The pain can be quite intense but is 
generally of short duration. The mechanism is thought to involve rapid 
expansion of the dominant follicle, although it also may be caused by 
peritoneal irritation by follicular fluid released at the time of ovulation.
Dysmenorrhea typically refers to the crampy lower abdominal mid­
line discomfort that begins with the onset of menstrual bleeding and 
gradually decreases over 12–72 h. It may be associated with nausea, 
diarrhea, fatigue, and headache and occurs in 60–93% of adolescents, 
beginning with the establishment of regular ovulatory cycles. Its preva­
lence decreases after pregnancy and can be treated effectively with 
hormonal contraceptives. Primary dysmenorrhea results, in a major­
ity of cases, from hormone-dependent prostaglandin (PG) pathway 
mechanisms that cause intense uterine contractions, decreased blood 
flow, and increased peripheral nerve hypersensitivity, resulting in pain. 
However, variability in response to cyclooxygenase inhibitors suggests 
that PG-independent pathways, such as platelet activating factor, may 
also mediate inflammation. Secondary dysmenorrhea refers to pain 
caused by underlying pelvic pathology.
Endometriosis results from the presence of endometrial glands and 
stroma outside the uterus. These deposits of ectopic endometrium 
respond to hormonal stimulation and may be associated with dysmen­
orrhea, painful intercourse, and painful bowel movements. On pelvic 
exam, adnexal tenderness may be present or tender nodules may be 
palpated along the uterosacral ligaments. Pain associated with endo­
metriosis can be cyclic or continuous, and the stage/severity of endo­
metriosis, as determined by laparoscopy, does not always correlate with 
the extent of pain. Transvaginal pelvic ultrasound is part of the initial 
workup and may detect an endometrioma within the ovary. Additional 
sonographic techniques can be used to identify deep endometriosis 
including nonmobile ovaries and rectovaginal or bladder nodules. 
The CA-125 level may be increased, but it has low negative predictive 
value. Pelvic MRI has higher sensitivity and specificity for diagnosis of 
endometriosis. Diagnostic laparoscopy is performed when patients do 
not respond adequately to empiric treatment and is considered the gold 
standard for diagnosis. If endometriosis is detected, the severity can be 
staged and the endometriotic lesions ablated or excised.
Large fibroids can cause chronic pelvic pain or pressure, and submu­
cosal fibroids may be associated with dysmenorrhea. Other secondary 
causes of dysmenorrhea include adenomyosis, a condition caused by 
the presence of ectopic endometrial glands and stroma within the myo­
metrium. Chronic PID may be associated with ongoing pelvic pain and 
is associated with tuberculosis or actinomycosis. Pelvic congestion syn­
drome is associated with pelvic varicosities with low blood flow, result­
ing in pelvic venous congestion. However, this is no clear evidence to 
indicate that this finding is associated with chronic pelvic pain.
TREATMENT
Chronic Pelvic Pain
DYSMENORRHEA
Local application of heat, exercise, sexual activity, a vegetarian diet, 
use of vitamins D, B1, B6, and E and fish oil, acupuncture, and yoga 
have all been suggested to be of benefit, but studies are not adequate 
to provide recommendations. However, NSAIDs are very effective 
and provide >80% sustained response rates. Ibuprofen, naproxen, 
ketoprofen, mefenamic acid, and nimesulide are all superior to 
placebo. For best response, treatment should be initiated prior to 
the onset of menses and continued for at least 2–3 days. Combined 
or progestin-only hormonal contraceptives taken cyclically or con­
tinuously effectively reduce symptoms of dysmenorrhea.
ENDOMETRIOSIS
Combined hormonal contraceptives or continuous progestin (either 
orally, implants, or a levonorgestrel IUD) is used for the treatment 
of endometriosis. Evidence of an endometrioma on ultrasound 

imaging can be medically managed and does not require surgi­
cal removal unless it increases in size or there is persistent pain. 
Patients who do not respond to medical management and lapa­
roscopic resection of endometriotic lesions can be offered GnRH 
agonist suppression with add-back therapy or aromatase inhibitors.
FIBROIDS
Chronic pain and dysmenorrhea associated with fibroids can be 
managed medically or surgically depending on the number and 
location of fibroids and associated symptoms. The U.S. Food and 
Drug Administration (FDA) approved the first two oral treat­
ments for uterine fibroids (elagolix with estradiol/norethindrone 
acetate and relugolix with estradiol/norethindrone acetate), and 
the selective progesterone receptor modulator ulipristal acetate was 
withdrawn in Europe and Canada. Medical management includes 
oral hormonal contraceptives, tranexamic acid, NSAIDs, proges­
tins, IUDs, and GnRH agonists and antagonists. Surgical man­
agement includes myomectomy, endometrial ablation/myolysis, 
radiofrequency volumetric thermal ablation, laparoscopic ablation, 
or hysterectomy. Chronic pain and dysmenorrhea associated with 
adenomyosis can be managed with combined hormonal treat­
ment, levonorgestrel IUD, or hysterectomy after child-bearing is 
complete.

Hirsutism
CHAPTER 406
■
■FURTHER READING
Bartels CB et al: An evidence-based approach to the medical man­
agement of fibroids: A systematic review. Clin Obstet Gynecol 59:30, 
2016.
Bloomfield H et al: Screening pelvic examinations in asymptomatic 
average risk adult women. WA-ESP Project #09-009; 2013.
Bouilly J et al: Identification of multiple gene mutations accounts for 
the new genetic architecture of ovarian insufficiency. J Clin Endocrinol 
Metab 101:4541, 2016.
Brunham RC et al: Pelvic inflammatory disease. N Engl J Med 
372:2039, 2015.
Fourman LR, Fazeli PK: Neuroendocrine causes of amenorrhea—An 
update. J Clin Endocrinol Metab 100:812, 2015.
Ju H et al: The prevalence and risk factors of dysmenorrhea. Epidem 
Rev 36:104, 2014.
Lee  IT, Barnhart  KT: What is an ectopic pregnancy? JAMA 329:434, 
2023.
Oladosu FA et al: Nonsteroidal anti-inflammatory drug resistance in 
dysmenorrhea: Epidemiology, causes, and treatment. Am J Obstet 
Gynecol 218:390, 2018.
Taylor HS et al: Endometriosis is a chronic systemic disease: Clinical 
challenges and novel innovations. Lancet 397:839, 2021.
Teede HJ et al: International PCOS Network. Recommendations from 
the 2023 International Evidence-based Guideline for the Assessment 
and Management of Polycystic Ovary Syndrome. Fertil Steril 120:767, 
2023.
David A. Ehrmann

Hirsutism
■
■DEFINING HIRSUTISM
Body hair can be categorized as either vellus (fine, soft, and not pig­
mented) or terminal (long, coarse, and pigmented). Approximately 10% 
of reproductive-age women have hirsutism, defined by the presence of 
excessive terminal hair growth. Hirsutism is most often idiopathic or 
the consequence of androgen excess associated with polycystic ovary

TABLE 406-1  Causes of Hirsutism
Gonadal hyperandrogenism
  Ovarian hyperandrogenism
  Polycystic ovary syndrome/functional ovarian hyperandrogenism
  Ovarian steroidogenic blocks
  Syndromes of extreme insulin resistance
  Ovarian neoplasms
  Hyperthecosis
Adrenal hyperandrogenism
  Premature adrenarche
  Functional adrenal hyperandrogenism
  Congenital adrenal hyperplasia (nonclassic and classic)
  Abnormal cortisol action/metabolism
  Adrenal neoplasms
Other endocrine disorders
  Cushing’s syndrome
  Hyperprolactinemia
  Acromegaly
Peripheral androgen overproduction
  Obesity
  Idiopathic
Pregnancy-related hyperandrogenism
  Hyperreactio luteinalis
  Thecoma of pregnancy
Drugs
  Androgens
  Oral contraceptives containing androgenic progestins
  Minoxidil
  Phenytoin
  Diazoxide
  Cyclosporine
  Valproic acid
Ovotesticular disorders of sex development
PART 12
Endocrinology and Metabolism
syndrome (PCOS). Less frequently, it results from adrenal androgen 
overproduction as occurs in nonclassic congenital adrenal hyperplasia 
(CAH) (Table 406-1).
Virilization refers to a condition that may the result from benign 
hyperplasia of ovarian theca and stroma cells (e.g., hyperthecosis); it 
may also be a harbinger of a serious underlying condition, such as an 
ovarian or adrenal neoplasm. In women with virilization, androgen 
levels are sufficiently high to cause deepening of the voice, breast atro­
phy, increased muscle bulk, clitoromegaly, and increased libido. Cuta­
neous manifestations commonly associated with hirsutism include 
acne and hair thinning or pattern hair loss (androgenic alopecia).
■
■HAIR FOLLICLE GROWTH AND 
DIFFERENTIATION
The number of hair follicles remains unchanged over the life span, but 
follicle size and the type of hair can change in response to numerous 
factors, particularly androgens. Androgens are necessary for terminal 
hair and sebaceous gland development and mediate differentiation 
of pilosebaceous units (PSUs) into a terminal hair follicle and/or a 
sebaceous gland. In the former case, androgens transform the vellus 
hair into a terminal hair; in the latter case, the sebaceous component 
proliferates and the hair remains vellus.
There are three phases in the cycle of hair growth: (1) anagen 
(growth phase), (2) catagen (involution phase), and (3) telogen (rest 
phase). Depending on the body site, hormonal regulation may play an 
important role in the hair growth cycle. Hair growth on the face, chest, 
upper abdomen, and back typically requires elevated androgen concen­
trations. However, there is only a modest correlation between androgen 
levels and the quantity of hair growth. This is due to the fact that hair 
growth from the follicle also depends on local growth factors, and the 
variability in end-organ (PSU) sensitivity to androgens. Genetic factors 

and ethnic background also influence hair growth. Androgen excess 
in women may result in hair thinning or loss because androgens cause 
scalp hairs to spend less time in the anagen phase.
In general, dark-haired individuals tend to be more hirsute than 
blond or fair individuals. Asians and Native Americans have relatively 
sparse hair in regions sensitive to high androgen levels, whereas people 
of Mediterranean descent are more hirsute.
■
■CLINICAL ASSESSMENT
Historic elements relevant to the assessment of hirsutism include the 
age at onset and rate of progression of hair growth and associated 
symptoms or signs (e.g., menstrual irregularity and acne). Depend­
ing on the cause, excess hair growth typically is first noted during 
the second and third decades of life. The growth is usually slow but 
progressive. Sudden development and rapid progression of hirsutism 
suggest the possibility of an androgen-secreting neoplasm, in which 
case virilization may also be present.
The age at onset of menstrual cycles (menarche) and the pattern of 
the menstrual cycle should be ascertained. Menses may be irregular in 
the first 2 years after menarche; oligomenorrhea (<8 cycles per calen­
dar year) thereafter is more likely to result from ovarian than adrenal 
androgen excess. Associated symptoms such as galactorrhea should 
prompt evaluation for hyperprolactinemia (Chap. 392) or possibly 
hypothyroidism (Chap. 394). Hypertension, striae, easy bruising, and 
centripetal weight gain suggest hypercortisolism (Cushing’s syndrome; 
Chap. 398). Rarely, patients with acromegaly present with hirsutism. 
Medications such as phenytoin, minoxidil, and cyclosporine may be 
associated with androgen-independent excess hair growth (i.e., hyper­
trichosis). A family history of infertility and/or hirsutism may indicate 
inherited disorders such as nonclassic CAH (Chap. 398).
Physical examination should include measurement of height and 
weight and calculation of body mass index (BMI). A BMI >25 kg/m2 is 
indicative of excess weight for height, and values >30 kg/m2 are often 
seen in association with hirsutism, probably the result of increased 
conversion of androgen precursors to testosterone. Notation should 
be made of blood pressure, as adrenal causes may be associated with 
hypertension. Cutaneous signs sometimes associated with androgen 
excess and insulin resistance include acanthosis nigricans and skin tags.
An objective clinical assessment of hair distribution and quantity 
is central to the evaluation in any woman presenting with concerns 
about excessive hair growth. This assessment permits the distinction 
between hirsutism and hypertrichosis and provides a baseline reference 
point to gauge the response to treatment. A simple and commonly used 
method to grade hair growth is the modified scale of Ferriman and 
Gallwey (Fig. 406-1), in which each of nine androgen-sensitive sites is 
graded from 0 (no hair growth) to 4 (hair growth typically seen in adult 
men). Although it is normal for most women to have some hair growth 
in androgen-sensitive sites, ~95% of non-Hispanic white and African 
American women have a score <8 on this scale. Scores >8 suggest excess 
androgen-mediated hair growth, a finding that should be assessed further 
by means of hormonal evaluation (see below). Asian and Native Ameri­
can women are less likely to manifest hirsutism, and the only cutaneous 
evidence of androgen excess may be pustular acne and thinning scalp hair.
■
■HORMONAL EVALUATION
Androgens are secreted by the ovaries and adrenal glands in response 
to their respective tropic hormones: luteinizing hormone (LH) and 
adrenocorticotropic hormone (ACTH). Testosterone is the principal 
circulating steroid involved in the etiology of hirsutism; other steroids 
that may contribute to the development of hirsutism include andro­
stenedione and dehydroepiandrosterone (DHEA) and its sulfated form 
(DHEAS). The ovaries and adrenal glands normally contribute about 
equally to testosterone production. Approximately half of the total tes­
tosterone originates from direct glandular secretion, and the remainder 
is derived from the peripheral conversion of androstenedione and 
DHEA (Chap. 393).
Testosterone is the most important circulating androgen, but it is a 
precursor hormone in mediating hirsutism. Testosterone is converted 
to dihydrotestosterone (DHT) by the enzyme 5α-reductase, which is

Upper lip

Chin

Chest

Abdomen

Pelvis

Upper arms

Thighs

Upper back

Lower back

FIGURE 406-1  Hirsutism scoring scale of Ferriman and Gallwey. The nine body areas that have androgen-sensitive areas are graded from 0 (no terminal hair) to 4 (frankly 
virile) to obtain a total score. A normal hirsutism score is <8. (Modified with permission from LJ DeGroot, JL Jameson: Endocrinology, 5th ed. Philadelphia, PA: Saunders; 
2006.)
located in the PSU. DHT is more potent than testosterone as it has a 
higher affinity for, and slower dissociation from, the androgen recep­
tor. The local production of DHT allows it to serve as the primary 
mediator of androgen action at the level of the PSU. There are two 
isoenzymes of 5α-reductase: type 2 is found in the prostate gland and 
in hair follicles, and type 1 is found primarily in sebaceous glands.

Hirsutism
CHAPTER 406

One approach to the evaluation and treatment of hirsutism is depicted 
in Fig. 406-2. In addition to measuring blood levels of testosterone 
and DHEAS, it is often important to measure the level of free (or 
unbound) testosterone, i.e., the fraction of testosterone that is not 
bound to its carrier protein, sex hormone–binding globulin (SHBG). 
Unbound testosterone is biologically available for conversion to DHT

Evaluation and Treatment of Hirsutism
Abnormal hirsutism score or
localized terminal hair growth
plus clinical evidence of a
hyperandrogenic disorder
Localized terminal hair growth (e.g., chin)
Trial of dermatologic
therapy
PART 12
Endocrinology and Metabolism
Course stable
or improving
Hair growth
progresses
Total testosterone blood
level by specialty assay
Normal
variant
Testosterone normal
Hirsutism moderate-severe and/or
other clinical evidence of
hyperandrogenic endocrine disorder
Hirsutism mild
and isolated
Hyperandrogenemia
Trial of dermatologic or
oral contraceptive therapy
Free testosterone blood level
(calculated from total testosterone
and SHBG or by LC/TMS)
Hair growth
progresses
Course stable
or improving
Free testosterone
normal
Idiopathic
hirsutism
Re-evaluate if hirsutism progresses
FIGURE 406-2  Algorithm for the evaluation and treatment of hirsutism. LC/TMS, liquid chromatography/tandem mass spectrometry; SHBG, sex hormone–binding globulin. 
(Reproduced with permission from KA Martin et al: Evaluation and treatment of hirsutism in premenopausal women: An endocrine society clinical practice guideline. J Clin 
Endocrinol Metab 103:1233, 2018.)
and binding to androgen receptors. Both hyperinsulinemia and andro­
gen excess decrease hepatic production of SHBG, resulting in levels of 
total testosterone within the high-normal range, whereas the unbound 
hormone is elevated more substantially. Although there is a decline in 
ovarian testosterone production after menopause, ovarian estrogen 
production decreases to an even greater extent, and the concentration 
of SHBG is reduced. Consequently, there is an increase in the relative 
proportion of unbound testosterone, and it may exacerbate hirsutism 
after menopause.
A baseline plasma total testosterone level >12 nmol/L (>3.5 ng/mL) 
usually indicates an androgen-producing tumor, whereas a level 
>7 nmol/L (>2 ng/mL) is suggestive of tumor but may also be observed 
in women with hyperthecosis. A basal DHEAS level >18.5 μmol/L 
(>7000 μg/L) suggests an adrenal tumor. Although DHEAS has been 
proposed as a “marker” of predominant adrenal androgen excess, it is 
not unusual to find modest elevations in DHEAS among women with 
PCOS. Computed tomography (CT) or magnetic resonance imaging 
(MRI) should be used to localize an adrenal mass, and transvaginal 
ultrasound usually suffices to identify an ovarian mass if clinical evalu­
ation and hormonal levels suggest these possibilities.
PCOS is the most common cause of ovarian androgen excess 
(Chap. 404). An increased ratio of LH to follicle-stimulating hor­
mone (FSH) is characteristic in carefully studied patients with PCOS. 
However, because of the pulsatile nature of gonadotropin secretion, a 
random measurement of LH and FSH may be misleading and is not 

Medication-related
hair growth
Discontinue
if possible
Testosterone elevated
Major hyperandrogenic
endocrine disorders to
consider:
• Polycystic ovary syndrome
• Nonclassic congenital
  adrenal hyperplasia
• Cushing’s syndrome
• Virilizing tumor
• Hyperprolactinemia
Free testosterone
elevated
recommended. Transvaginal ultrasound classically shows enlarged 
ovaries, increased stroma, and multiple “cysts” in women with PCOS. 
These so-called cysts are, in fact, preantral and early antral follicles 
that result from abnormal follicular maturation. “Cystic” ovaries also 
may be found in women with hypothalamic amenorrhea (Chap. 404) 
and even among women without clinical or laboratory features of 
PCOS. Thus, ultrasonography is often not needed to diagnose PCOS 
given its relatively low specificity and its high degree of operator 
dependence.
Because adrenal androgens are readily suppressed by low doses of 
glucocorticoids, the dexamethasone androgen-suppression test may 
broadly distinguish ovarian from adrenal androgen overproduction. 
A blood sample is obtained before and after the administration of 
dexamethasone (0.5 mg orally every 6 h for 4 days). An adrenal source 
is suggested by suppression of unbound testosterone into the normal 
range; incomplete suppression suggests ovarian androgen excess. An 
overnight 1-mg dexamethasone suppression test, with measurement 
of 8:00 a.m. serum cortisol, is useful when there is clinical suspicion of 
Cushing’s syndrome (Chap. 398).
Nonclassic CAH is most commonly due to 21-hydroxylase defi­
ciency but also can be caused by autosomal recessive defects in other 
steroidogenic enzymes necessary for adrenal corticosteroid synthesis 
(Chap. 398). Because of the enzyme defect, the adrenal gland cannot 
secrete glucocorticoids (especially cortisol) efficiently. This results 
in diminished negative feedback inhibition of ACTH, leading to

compensatory adrenal hyperplasia and the accumulation of steroid 
precursors that subsequently are converted to androgen. Deficiency of 
21-hydroxylase can be reliably excluded by determining a morning 
17-hydroxyprogesterone level <6 nmol/L (<2 μg/L) (drawn in the 
follicular phase). Alternatively, 21-hydroxylase deficiency can be diag­
nosed by measurement of 17-hydroxyprogesterone 1 h after the admin­
istration of 250 μg of synthetic ACTH (cosyntropin) intravenously.
TREATMENT
Hirsutism
Treatment of hirsutism may be accomplished pharmacologically 
or by mechanical means of hair removal. Nonpharmacologic treat­
ments should be considered in all patients either as the only treat­
ment or as an adjunct to drug therapy.
Nonpharmacologic treatments include (1) bleaching, (2) removal 
of the hair from the skin surface by shaving or with chemical treat­
ments, and (3) depilatory (removal of the hair including the root) 
such as plucking, waxing, electrolysis, laser, and intense pulsed 
light (IPL). Despite perceptions to the contrary, shaving does not 
increase the rate or density of hair growth. Chemical depilatory 
treatments may be useful for mild hirsutism that affects only limited 
skin areas, although they can cause skin irritation. Wax treatment 
removes hair temporarily but is uncomfortable. Electrolysis is effec­
tive for more permanent hair removal, particularly in the hands of 
a skilled electrologist. Laser and IPL are used to treat large areas of 
pigmented, terminal hair. Light of specific wavelength, duration, 
and energy is absorbed by melanin in the hair shaft and follicle lead­
ing to photothermolysis. Properly delivered, this treatment delays 
hair regrowth and causes permanent hair removal in many patients.
Pharmacologic therapy is directed at interrupting one or more 
of the steps in the pathway of androgen synthesis and action: 
(1) suppression of adrenal and/or ovarian androgen production, 
(2) enhancement of androgen-binding to plasma-binding proteins, 
particularly SHBG, (3) impairment of the peripheral conversion 
of androgen precursors to active androgen, and (4) inhibition of 
androgen action at the target tissue level. Attenuation of hair growth 
is typically not evident until 4–6 months after initiation of medical 
treatment and, in most cases, leads to only a modest reduction in 
hair growth.
Combination estrogen-progestin therapy in the form of an oral 
contraceptive is usually the first-line endocrine treatment for hirsut­
ism and acne, after dermatologic management. The estrogenic com­
ponent of most oral contraceptives currently in use is either ethinyl 
estradiol or mestranol. The suppression of LH leads to reduced 
production of ovarian androgens. The reduced androgen levels also 
result in a dose-related increase in SHBG, thus lowering the fraction 
of unbound plasma testosterone. Estrogens also have a direct, dosedependent suppressive effect on sebaceous cell function.
The choice of a specific oral contraceptive should be predi­
cated on the progestational component, as progestins vary in 
their suppressive effect on SHBG levels and in their androgenic 
potential. Ethynodiol diacetate has relatively low androgenic poten­
tial, whereas progestins such as norgestrel and levonorgestrel are 
particularly androgenic, as judged from their attenuation of the 
estrogen-induced increase in SHBG. Norgestimate exemplifies 
the newer generation of progestins that are virtually “nonandro­
genic.” Drospirenone, an analogue of spironolactone that has both 
antimineralocorticoid and antiandrogenic activities, is often used 
as a progestational agent in combination with ethinyl estradiol, 
although concern remains about is prothrombotic effects.
Oral contraceptives are contraindicated in women with a his­
tory of thromboembolic disease and women with increased risk of 
breast or other estrogen-dependent cancers (Chap. 407). There is a 
relative contraindication to the use of oral contraceptives in smok­
ers and those with hypertension or a history of migraine headaches. 
Improvements in hirsutism are typically in the range of 20%, but 
there may be an arrest of further progression of hair growth. In 

most trials, estrogen-progestin therapy alone improves the extent 
of acne by an average of 50%. The effect on hair growth may not 
be evident for 6 months, and the maximum effect may require 
9–12 months owing to the length of the hair growth cycle

Because oral contraceptives are efficacious and have fewer side 
effects, they are recommended over glucocorticoids as first-line 
treatment of hirsutism in CAH. If the response to oral contracep­
tives is inadequate, glucocorticoids may be used. The lowest effec­
tive dose of glucocorticoid should be used (e.g., dexamethasone 
[0.2–0.5 mg] or prednisone [5–10 mg]) taken at bedtime to achieve 
maximal suppression by inhibiting the nocturnal surge of ACTH.
Hirsutism
CHAPTER 406
Cyproterone acetate is the prototypic antiandrogen. It acts 
mainly by competitive inhibition of the binding of testosterone 
and DHT to the androgen receptor. In addition, it may enhance the 
metabolic clearance of testosterone by inducing hepatic enzymes. 
Although not available for use in the United States, cyproterone 
acetate is widely used in Canada, Mexico, and Europe. Cyproterone 
(50–100 mg) is given on days 1–15, and ethinyl estradiol (50 μg) 
is given on days 5–26 of the menstrual cycle. Side effects include 
irregular uterine bleeding, nausea, headache, fatigue, weight gain, 
and decreased libido.
Spironolactone, which usually is used as a mineralocorticoid 
antagonist, is also a weak antiandrogen. It is almost as effective as 
cyproterone acetate when used at high enough doses (100–200 mg 
daily). Patients should be monitored intermittently for hyperkale­
mia or hypotension, though these side effects are uncommon. Preg­
nancy should be avoided because of the risk of feminization of a 
male fetus. Spironolactone can also cause menstrual irregularity. It 
often is used in combination with an oral contraceptive, which sup­
presses ovarian androgen production and helps prevent pregnancy.
Flutamide is a potent nonsteroidal antiandrogen that is effective 
in treating hirsutism, but concerns about the induction of hepato­
cellular dysfunction preclude its use. Finasteride is a competitive 
inhibitor of 5α-reductase type 2. Beneficial effects on hirsutism 
have been reported, but the predominance of 5α-reductase type 
1 in the PSU appears to account for its limited efficacy. Finaste­
ride would also be expected to impair sexual differentiation in a 
male fetus, and it should not be used in women who may become 
pregnant. Although studies of dutasteride are limited in number, 
it appears that this agent may have efficacy in treating scalp hair 
thinning and loss as well as hirsutism. Dutasteride differs from 
finasteride as it targets both 5α-reductase types 1 and 2.
Ultimately, the choice of any specific agent(s) must be tailored to 
the unique needs of the patient being treated. As noted previously, 
pharmacologic treatments for hirsutism should be used in conjunc­
tion with nonpharmacologic approaches. It is also helpful to review 
the pattern of female hair distribution in the normal population to 
dispel unrealistic expectations.
■
■FURTHER READING
Azarchi S et al: Androgens in women: Hormone-modulating thera­
pies for skin disease. J Am Acad Derm 80:1509, 2019.
Brown DL et al: Ovarian stromal hyperthecosis: Sonographic features 
and histologic associations. J Ultrasound Med 28:587, 2009.
Forslund  M et al: Different kinds of oral contraceptive pills in poly­
cystic ovary syndrome: A systematic review and meta-analysis Eur J 
Endocrinol 189:S1, 2023.
Haak CS et al: Hair removal in hirsute women with normal testoster­
one levels: A randomized controlled trial of long-pulsed diode laser 
vs. intense pulsed light. Br J Dermatol 163:1007, 2010.
Martin KA et al: Evaluation and treatment of hirsutism in premeno­
pausal women: An Endocrine Society clinical practice guideline. J Clin 
Endocrinol Metab 103:1233, 2018.
McCartney CR, Marshall JC: Polycystic ovary syndrome. N Engl J 
Med 375:1398, 2016.
Rosenfield RL, Ehrmann DA: The pathogenesis of polycystic ovary 
syndrome (PCOS): The hypothesis of PCOS as functional ovarian 
hyperandrogenism revisited. Endocr Rev 37:467, 2016.