Some prescription oral medications have been found to affect hair growth. They can be helpful in reducing hair growth in some conaumers, but it’s important to discuss possible unwanted side effects with your physician.
Drugs that can reduce hair growth
Spironolactone (also known as Aldactone) is arguably the number one hirsutism treatment of choice for dermatologists in the US. Spironolactone has antiandrogenic effects that may enhance treatment of several androgen-excess conditions, particularly severe hirsutism.
Spironolactone has several properties that make it suitable for use in treating hirsutism. It interferes with the production of testosterone and it increases the metabolism of any testosterone that is produced. Spironolactone binds to cell androgen receptors and blocks them from binding to naturally produced androgens. In addition with long term spironolactone use, there is a gradual reduction in 5 alpha reductase activity. It is this enzyme that converts testosterone to the more potent, hair follicle stimulating, dihydrotestosterone.
Treatment protocols may involve continuous spironolactone use at 50mg to 200mg per day or cyclic use. For example 50mg or 100mg twice daily from the 4th to the 22nd day of the menstrual cycle. Numerous treatment protocols involving spironolactone have been used in different studies, but no particular treatment approach has been shown to be significantly superior. Combination therapy with an oral contraceptive pill or dexamethasone appears to have an improved beneficial effect on hirsutism and limits side effects.
Spironoolactone is a diuretic, so it’s advised to drink plenty of water while taking it. Side effects with spironolactone are generally transient. As with all antiandrogens , spironolactone use should be avoided during pregnancy and in women who have a family history of breast cancer, although there is no proven association between spironolactone and breast malignancy.
Finasteride (marketed as Propecia and Proscar)
Promoted for use in treating pattern baldness and benign prostate hyperplasia, respectively, it’s a type II 5alpha reductase inhibitor. This enzyme blocks the conversion of testosterone to dihydrotestosterone (DHT), a potent stimulator of hair loss in scalp follicles and hair growth in body hair follicles that have androgen receptors.
When finasteride was tested on postmenopausal women with pattern baldness there was little or no response. However, in trials for hirsutism finasteride has some significant promise. Results with finasteride alone in some trials have been comparable with oral antiandrogens, and the combination of finasteride plus other antiandrogens have shown an improved effect over using treatments separately. Although it may not be an appropriate treatment in every situation, finasteride is a readily available and relatively safe treatment option. The most significant side effect is that male fetuses will develop with female genitalia in any pregnant woman using finasteride. Consequently, dermatologists ensure one or more forms of birth control are used by any woman using finasteride. Other side effects reported include breast enlargement and increased libido (in contrast to decreased libido in men).
Flutamide is a potent antiandrogen that strongly binds to androgen receptors on cells in hair follicles. The binding of Flutamide to cell androgen receptors blocks androgens from stimulating hair growth.
Studies that compare flutamide to spironolactone or cyproterone acetate suggest that overall the beneficial effects on reducing hirsutism are similar. Some suggest flutamide is slightly superior and others say it is slightly less superior. Initially flutamide was given to patients at high dose rates of up to 250mg three times a day. However more recent studies indicate that a similar improvement in hirsutism can be obtained with flutamide doses as low as 62.5mg a day. The reduction in dose significantly reduces the risk of side effects.
For a small subgroup of women flutamide and other oral antiandrogens are highly toxic. Between February 1989 and December 1994 the Food and Drug Administration (FDA) received reports of 20 patients who died and 26 who were hospitalized for hepatotoxicity due to flutamide, a rate around 3 per 10,000 flutamide users. Early symptoms of hepatotoxicity include nausea, vomiting, fatigue and jaundice and if such symptoms occur they must be immediately reported to a doctor. Dermatologists generally recommend that serial blood aminotransferase levels should be monitored during the first few months of flutamide treatment. Any adverse aminotransferase level changes suggest that hepatotoxicity is a significant risk and flutamide use should be stopped. For this and other reasons, some dermatologists do not use flutamide to treat hirsutism however, the side effect risk of flutamide is no better or worse than other oral antiandrogens
Cyproterone acetate (not available in the US)
Cyproterone acetate (CPA) was first used to treat hirsutism experimentally in 1965 and was brought to the attention of dermatologists by Hammerstein and colleagues in Germany. Since then it has become a very popular oral antiandrogen in Europe, Canada, and South America. Flutamide may have slightly a superior ability to reduce hirsutism as compared to CPA, but CPA is significantly cheaper than Flutamide and so is a popular choice in those countries where CPA is available.
Some dermatologists suggest that the effects of spironolactone are somewhat inferior to cyproterone acetate (CPA). However, CPA is not available in the US.
Several different treatment approaches have been tried with CPA. 50-100mg per day of CPA orally on days 1-10 of the menstrual cycle along with a triphasic oral contraceptive is a popular treatment regime with some dermatologists, particularly in Mediterranean countries. However, this is regarded as overkill by some Northern European dermatologists who specialize in treating hair conditions. Dosages of 100mg CPA per day are used for people with ovarian tumors or for sex offenders, but may not be necessary for treating idiopathic hirsutism. Several studies comparing different CPA dosage rates have shown no significant difference in the treatment of hirsutism when using 100mg or 2mg of CPA. A few dermatologists use high dose CPA initially and then drop the dosage for long term use.
Low dose CPA treatment protocols include; oral ingestion of 2mg CPA plus estradiol on days 5-25 of the menstrual cycle, or just 1mg of CPA on days 12 to 21 of the menstrual cycle plus estradiol for 21 days. Low dose CPA use reduces the risk of side effects while having similar positive benefits in treating hirsutism. There are many other protocols for treating hirsutism using different CPA doses or different times of application during the monthly cycle. No clear advantage has been demonstrated for a particular CPA treatment regime and the personal preference of the dermatologist seems to be the greatest factor in deciding CPA dose levels.
CPA is not available in the US in any form and only certain formulations of CPA are available in other countries. The most commonly available form of CPA is in combination with estradiol in tablets called Diane 35 and Dianette- actually the exact same drug, just marketed under different names. In Canada, it is called Diane 35. In the UK and Europe it is called Dianette. Both have 35 mcg of ethinylestradiol and 2 mg CPA. Diane 50 has 50 mcg of ethinylestradiol and 2 mg CPA. However, this drug is NOT available in Canada. CPA in its various forms is made by the Germany based Schering AG pharmaceutical company.
The Dianette tablets have a significant property in that they increase sex hormone binding globulin (SHBG) levels in the blood whereas the lower estradiol dose in Diane does not. The increase in SHBG has a positive benefit as SHBG binds to testosterone and stops it from being converted to dihydrotestosterone and having an affect on hair follicles. However, high dose estradiol is potentially toxic and some women are unable to tolerate the negative effects of Dianette.
CPA and estradiol combined also has potential to induce other side effects. Some suspicions have been cast on long term CPA and estradiol use and the potential for a reduction in bone mass. However, recent research studies suggest there are no apparent negative effects. Other side effect risks include weight gain, fatigue, nausea, headaches, depression, and impairment of liver function. Some dermatologists recommend testing vitamin B12 levels in CPA users. CPA can cause B12 levels to drop and this can lead to depression or anxiety problems. Vitamin B12 supplements can rectify the problem.
As with all systemic antiandrogens, serious side effects will develop in a male embryo of a pregnant user. Although CPA is a powerful proestrogen it does not necessarily stop ovulation. Consequently, contraception with cyclical estrogen supplements is vital when using CPA.
Ketoconazole is a relatively new and particularly potent anti androgen drug. Since 1985 there have been various studies suggesting that ketoconazole could be used to treat hirsutism. Ketoconazole works by blocking the production of hormones by the ovaries and the adrenal glands.
As with other antiandrogen drugs, there are several different research reports that claim a reduction in hirsutism with different drug use protocols. The intake of ketoconazole may range from 200mg to 400mg a day.
Although the list of references below might seem to suggest that ketoconazole is a popular treatment for hirsutism, most dermatologists are wary of using it on a regular basis. Because it is such a powerful anti androgen, some dermatologists believe the risk of side effects is greater than with other antiandrogen drugs. Dermatologists are particularly concerned with the risk of hepatotoxicity when using ketoconazole. Most dermatologists only use ketoconazole when the hirsutism is particularly pronounced and even then the drug is only prescribed for a brief period of time before switching to other antiandrogen drugs.
Gonadotrophin releasing hormone agonists
Gonadotrophin releasing hormone agonists (GnRH) have been suggested as potential treatments for hirsutism. The most common GnRH agonists used are leuprolide acetate, buserelin and decapeptyl. GnRH agonists are drugs that decrease ovarian steroid production and some studies show that GnRH agonists could be very effective for treating hirsutism where ovarian hyperandrogenism (too much androgen production by the ovaries) is the problem. However, the effect of GnRH agonists is on ovarian production so they are not very effective for hirsutism where the root cause is over activity of the adrenal glands.
GnRH agonists are still primarily an experimental treatment. Some studies suggest that addition of GnRH agonists to treatment using antiandrogen drugs prolongs remission of hirsutism. GnRH agonists have to be taken along with hormone replacement therapy (often called “add back treatment”) as the GnRH agonist shuts down ovarian hormone production almost completely so while androgens are no longer produced, neither are estrogens and progesterones. Hormone replacement is particularly important as using GnRH agonists without estrogen and progesterone supplements bone density decreases significantly.
The greatest barrier to wide spread use of GnRH agonists is that the drugs are quite expensive compared to cyproterone acetate or spironolactone.
For a bibliography , see the discussion of prescription oral medical data.