Hair loss is not life-threatening, but it can be distressing, especially when you don’t know what’s causing it. Some medications cause hair loss. Depending on the medication’s effect on the hair follicle, hair can thin or come out in clumps. While many medications can cause hair loss, not everyone who takes the medication experiences this side effect.
A wide range of medications can cause hair loss. In some medications, such as some chemotherapy drugs, hair loss is an expected side effect. In other medications, it is a rare side effect. Regardless, most of the time, hair regrows after the medication is discontinued. If your hair is slow to regrow, medications like finasteride can stimulate hair regrowth.
Hair grows through a cycle, and then it is shed. There are three phases to the cycle: 1
Anagen effluvium usually affects growing hairs scattered all over your head. The onset may be rapid and cause widespread hair loss. Telogen effluvium causes hair to come out in clumps because it has prematurely entered its resting phase. Telogen effluvium causes hair loss three to five months after the trigger and is typically self-limiting.2
Medications that are known to cause hair loss as a side effect:
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Chemotherapy agents cause anagen effluvium in about 65% of people who need these medications.
The chemotherapy agents most likely to cause hair loss include:3
Diffuse hair loss begins days to weeks after the medication is started. Chemotherapy agents block cell division as part of their mechanism of action. Medical treatments to prevent chemotherapy-induced hair loss have not been effective. Minoxidil may help regrow hair after chemotherapy.2
Amphetamines are used to treat obesity, narcolepsy, and attention-deficit disorder. Amphetamines are stimulants that can cause addiction, anxiety, heart arrhythmias, nausea, and weight loss, among other side effects. Hair loss is a rare, but possible, side effect.4
Anticoagulants are medications that are used to prevent blood clots. Anticoagulants can be divided into traditional anticoagulants, coumadin and heparin, and newer direct oral anticoagulants (DOACs).
Heparin causes hair loss in about 54% to 66% of patients. Coumadin causes hair loss in 30% to 40% of patients. Hair loss is thought to occur by telogen effluvium, so it may be more gradual in onset.
DOACs can also cause hair loss. In one study, researchers estimated hair loss occurred in 4.4 patients per 100 patient-years of use.1
Anticonvulsants are medications used to prevent seizures. In one study, hair loss was reported by 19% of patients. Hair loss was most commonly reported by patients taking valproic acid.5 Hair loss after using valproic acid is typically transient, may be dose dependent, and affects less than 18% of patients.
Other antiseizure medications with which patients report hair loss include:6
Antihypertensives are medications used to lower blood pressure. Beta-blockers and ACE inhibitors are two classes of antihypertensives that are more commonly associated with hair loss. Some people will notice hair loss with one class of blood pressure medications but not with another.7 Hair loss will probably resolve once the medication is discontinued. Never discontinue your blood pressure medication without talking with your healthcare provider.
Metoprolol and propranolol are beta-blockers that may cause hair loss that is typically reversible once the medication is discontinued. Captopril is an ACE inhibitor that causes diffuse hair loss.
Antimicrobials are medications used to treat bacterial, viral, and fungal infections. For example, isoniazid is a medication used to treat tuberculosis. Though it is unclear how isoniazid causes hair loss, there are several case reports describing this side effect. Other medications used to treat tuberculosis can also cause hair loss.
Antiretroviral medications used to treat human immunodeficiency virus (HIV) can cause hair loss. When multiple antiretroviral medications are combined, hair loss may be more severe.8
Thyroid conditions may cause hair loss if they are untreated. Severe hypothyroidism (low thyroid) and hyperthyroidism (excess thyroid hormone) can both cause hair loss. Hair loss with thyroid disease is diffuse. Hair generally regrows once thyroid disease is treated, though, according to the British Thyroid Foundation, it may take months and be only partial regrowth.
Thyroid medications, such as carbimazole and propylthiouracil, can also cause hair loss, but it is a rare side effect.9
Colchicine is a medication used to treat gout. Hair loss or hair thinning is a less common side effect associated with colchicine use.
Allopurinol is another medication commonly prescribed to treat gout. It can cause hair loss that is typically temporary and reversible when the medication is discontinued.
Interferons are used to treat viral infections, some cancers, and some autoimmune conditions. Interferons can cause reversible hair discoloration, increased hair growth (hypertrichosis), and hair loss.10
Cholesterol-lowering medications called statins may rarely cause hair loss, according to anecdotal reports.
Hair loss from NSAIDs, such as naproxen and ibuprofen, is a rare side effect.
Psychotropic medications include mood stabilizers and antidepressants. Antidepressants are a class of medication that is used to treat mood disorders such as depression, anxiety, and bipolar disorder.
In one study investigating antidepressants and hair loss:11
Studies show other antidepressants can cause hair loss, including:12
Lithium and sodium valproate are mood stabilizers that are potential causes of hair loss. Approximately 12% of people taking lithium experience hair loss, and even more report hair thinning. Hair loss typically begins four to six months after starting the medication. Lithium can cause thyroid abnormalities, which can also contribute to hair loss.
Sodium valproate also causes hair loss in a dose-dependent manner. Hair loss appears to be transient and resolves once the medication is discontinued. Carbamazepine rarely causes hair loss.8
Retinoids are vitamin A derivatives used to treat acne and reduce the signs of aging. The most common side effects associated with retinoids are dry skin and mucous membranes. Hair loss is reported in about 13% of patients who use retinoids, with a median onset of four weeks.
Researchers in one study found that 3.2% of patients on a retinoid dose of less than 0.5mg/kg/d experienced hair loss, while 5.7% of patients on a higher dose did. Retinoids prematurely transition hair follicles from the anagen to the telogen phase.13
When combined with minoxidil, topical retinoids seem to increase minoxidil’s hair-regrowing effect. 14
Finasteride is a Type II 5α-reductase competitive inhibitor that decreases your body’s ability to convert testosterone to dihydrotestosterone (DHT). In genetically susceptible people, DHT shortens the growth phase of hair from years to weeks or months and decreases the hair follicle size. Finasteride reduces the amount of circulating DHT in the body by approximately two-thirds and slightly increases testosterone levels.
Start a treatment plan with Finasteride today!
While we strive to always provide accurate, current, and safe advice in all of our articles and guides, it’s important to stress that they are no substitute for medical advice from a doctor or healthcare provider. You should always consult a practicing professional who can diagnose your specific case. The content we’ve included in this guide is merely meant to be informational and does not constitute medical advice.
1. Watras MM, Patel JP, Arya R. Traditional Anticoagulants and Hair Loss: A Role for Direct Oral Anticoagulants? A Review of the Literature. Drugs Real World Outcomes. Mar 2016;3(1):1-6. doi:10.1007/s40801-015-0056-z
2. Phillips TG, Slomiany WP, Allison R. Hair Loss: Common Causes and Treatment. Am Fam Physician. Sep 15 2017;96(6):371-378.
3. Kanwar AJ, Narang T. Anagen effluvium. Indian J Dermatol Venereol Leprol. Sep-Oct 2013;79(5):604-12. doi:10.4103/0378-6323.116728
4. Meaux TA, McMahon PM, Jones GN, Bush AE, Kennedy JJ, Poche GW. Association of Alopecia Areata With Attention-Deficit/Hyperactivity Disorder Stimulant Medication: A Case-Control Study. Ochsner Journal. 2021;21(2):139-142. doi:10.31486/toj.20.0025
5. Chen B, Choi H, Hirsch LJ, et al. Cosmetic side effects of antiepileptic drugs in adults with epilepsy. Epilepsy Behav. Jan 2015;42:129-37. doi:10.1016/j.yebeh.2014.10.021
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7. Kataria V, Wang H, Wald JW, Phan YL. Lisinopril-Induced Alopecia: A Case Report. J Pharm Pract. Oct 2017;30(5):562-566. doi:10.1177/0897190016652554
8. Patel M, Harrison S, Sinclair R. Drugs and hair loss. Dermatol Clin. Jan 2013;31(1):67-73. doi:10.1016/j.det.2012.08.002
9. British Thyroid Foundation. Hair loss and thyroid disorders. https://www.btf-thyroid.org/hair-loss-and-thyroid-disorders
10. Taliani G, Biliotti E, Capanni M, Tozzi A, Bresci S, Pimpinelli N. Reversible alopecia universalis during treatment with PEG-interferon and ribavirin for chronic hepatitis C. J Chemother. Apr 2005;17(2):212-4. doi:10.1179/joc.2005.17.2.212
11. Etminan M, Sodhi M, Procyshyn RM, Guo M, Carleton BC. Risk of hair loss with different antidepressants: a comparative retrospective cohort study. Int Clin Psychopharmacol. Jan 2018;33(1):44-48. doi:10.1097/yic.0000000000000191
12. Tirmazi SI, Imran H, Rasheed A, Mushtaq S. Escitalopram-Induced Hair Loss. Prim Care Companion CNS Disord. Jun 25 2020;22(4)doi:10.4088/PCC.19l02496
13. Lytvyn Y, McDonald K, Mufti A, Beecker J. Comparing the frequency of isotretinoin-induced hair loss at <0.5-mg/kg/d versus ≥0.5-mg/kg/d dosing in acne patients: A systematic review. JAAD International. 2022;6:125-142. doi:10.1016/j.jdin.2022.01.002
14. Sharma A, Goren A, Dhurat R, et al. Tretinoin enhances minoxidil response in androgenetic alopecia patients by upregulating follicular sulfotransferase enzymes. Dermatol Ther. May 2019;32(3):e12915. doi:10.1111/dth.12915