What Medications Can Cause Hair Loss? 46 Known Drugs

Losing your hair or dealing with baldness can be incredibly frustrating.

As you age, it's also not altogether unexpected: a majority of men will deal with hair loss sometime in their life due to natural causes, but it can be delayed -- and hair restored -- with proper hair loss treatment.

But medications for other conditions can also cause hair loss, and certain drugs can contribute not only to hair loss but excessive hair growth and changes in color and texture as well. 

There's good news though, as these changes in your hair are typically reversible once you stop taking the drug that’s causing them. Here's what you should know about medications and hair loss.

How Can Medication Cause Hair Loss?

Some medications can cause hair loss because they interfere with the normal cycle of scalp hair growth. Healthy hair growth will occur at a rate of roughly 0.35 millimeters per day, which is roughly half of an inch per month. In addition, most healthy men and women will have between 80,000 and 120,000 terminal hairs on their scalp. 

Hair follicles, of which you have tens of thousands on your head, each cycle through three primary phases: anagen, catagen, and telogen.

1. Anagen is the growth phase and lasts two to six years, during which primary hair growth occurs. At any given time, nearly 85% and 90% of hair follicles are in this growth phase.
2. Catagen is the transitional stage of a hair follicle and occurs when the hair follicle experiences regression. The hair is still growing but the rate will be slowing down more and more. 
3. Telogen is a resting phase that normally lasts around three months. When this phase ends, inactive or dead hair is shed. It’s normal to shed around 100 or so hairs every day as a result.

Medications can lead to two different types of hair loss: telogen effluvium and anagen effluvium. 

Telogen Effluvium

Telogen effluvium is the most common form of drug induced hair loss and will usually appear within two to four months after you start taking a new drug. This condition causes the hair follicles to go into their resting phase (telogen) much earlier than normal and fall out before they should. People with telogen effluvium will usually shed between 30% and 70% more than the normal 100 or so hairs a day. 

Anagen Effluvium

Anagen effluvium is less common, but will occur during the anagen phase of the hair cycle, when the hairs are still actively growing. It will prevent the matrix cells, which are responsible for the production of new hairs, from dividing normally. This type of hair loss will usually occur within a few days or weeks after you start taking the medication responsible. 

It’s most common with people undergoing chemotherapy drugs for cancer and is often severe, resulting in people losing most or all of the hair on their head, in addition to their eyebrows, eyelashes, and other body hairs. 

How To Diagnose Drug Induced Hair Loss

If you think that you may be experiencing hair loss as a result of a medication, you should speak with a healthcare professional, particularly the doctor that prescribed the suspect medication. Some of the early signs of excessive hair loss include an increased amount of hair on your pillow, more hair on your brush, and more hair in the shower drain. 

Whenever a doctor is attempting to diagnose drug induced alopecia, they will take a complete medical history in order to account for the new medications, changes to doses, and family history of hair loss. 

How Can You Treat Drug Induced Hair Loss?

There is a very likely chance that if you're experiencing hair loss primarily as a result of a drug you're taking, the hair will grow back on its own once you stop taking the medication. It’s important to talk to your doctor before stopping, as the medication is certainly a necessary one for whatever medical condition it’s treating. However, if stopping the drug does not improve hair thinning, you may need to be treated with finasteride (Propecia) or minoxidil (Rogaine), medications that are known to slow hair loss and stimulate new hair growth.

46 Known Drugs That Can Cause Hair Loss

Drug induced alopecia, hair loss that develops due to a side effect of medication, will often occur within three months after starting the particular medication, but the exact timeline will depend on a few factors. The type of drug, type of hair loss, dosage, and your sensitivity to the drug are all important factors in how severe the side effects will be. 

Telogen Effluvium

Telogen effluvium is the more common type of drug induced hair loss and can develop as a possible side effect from a wide variety of medications and supplements. While hair loss is possible whenever using these drugs, it's actually a relatively rare side effect, and a large majority of people will not experience it. 

That being said, these are the types of medications, and a few examples, of drugs that have listed hair loss as possible side effect: 

• Acne medication, such as isotretinoin (Absorica and Accutane) 

• Antibiotics, such as penicillin, cephalexin, and erythromycin 

• Angiotensin converting enzyme (ACE) inhibitors, such as captopril (Capoten), enalapril (Vasotec), and lisinopril (Prinivil and Zestril)  

• Anti clotting drugs, such as heparin and warfarin

• Antifungal drugs, such as ketoconazole and voriconazole

• Antidepressants and mood stabilizers, such as paroxetine (Paxil), fluoxetine (Prozac), sertraline (Zoloft), protriptyline (Vivactil), and amitriptyline (Elavil)

• Anticonvulsants and anti seizure medications, such as divalproex (Depakote) and trimethadione (Tridione)

• Antiarrhythmic medications, such as amiodarone (Cordarone and Pacerone)

• Beta blockers, such as metoprolol (Lopressor), timolol (Blocadren), propranolol (Inderal), atenolol (Tenormin), and nadolol (Corgard)

• Birth control pills

• Blood thinners, such as heparin and warfarin (Coumadin)

• Cholesterol lowering drugs, such as clofibrate (Atromid-S), gemfibrozil (Lopid), atorvastatin (Lipitor), and simvastatin (Zocor)

• Gout medication, such as colchicine and allopurinol (Zyloprim and Lopurin)

• Hormone replacement therapy, such as progesterone and estrogen 

• Immunosuppressants, such as methotrexate, leflunomide (Arava), cyclophosphamide (Cytoxan), and etanercept (Enbrel)

• Nonsteroidal anti inflammatory drugs (NSAIDs), such as naproxen (Naprosyn)

• Parkinson’s disease drugs, such as levodopa (Atamet)

• Psoriasis medications, such as acitretin (Soriatane)

• Steroids, such as testosterone, progesteron, medroxyprogesterone (Depo-Provera), Provera, and Prometrium

• Stomach medications, such as famotidine (Pepcid) and cimetidine (Tagamet)

• Thyroid medications, such as carbimazole and propylthiouracil

• Vitamin A in high doses

• Weight loss drugs, such as phentermine

Anagen Effluvium

Anagen effluvium is most commonly associated with chemotherapy induced alopecia, as it will often be triggered by agents used for a variety of cancer therapies such as antimetabolites, alkylating agents, and mitotic inhibitors. Chemotherapy induced hair loss occurs with an estimated incidence rate of 65%. 

According to the American Society of Clinical Oncology, these are some of the chemotherapy drugs most likely to lead to hair loss or thinning:

• Adriamycin

• Altretamine (Hexalen)

• Carboplatin (Paraplatin)

• Cisplatin (Platinol)

• Cyclophosphamide (Neosar)

• Dactinomycin

• Daunorubicin

• Docetaxel (Taxotere)

• Doxorubicin (Adriamycin and Doxil)

• Epirubicin (Ellence)

• Etoposide

• Fluorouracil (5-FU)

• Gemcitabine (Gemzar)

• Idarubicin (Idamycin)

• Ifosfamide (Ifex)

• Irinotecan

• Methotrexate

• Nitrosoureas

• Paclitaxel

• Tamoxifen

• Topotecan

• Vincristine (Marqibo and Vincasar)

• Vinorelbine (Alcorest and Navelbine)

The Takeaway: While there are many drugs and medications that may result in hair loss, it's not the primary cause of hair loss for most people. Stopping the medication, if appropriate, can often reverse the effects, while FDA-approved hair loss treatments are known for their effectiveness as well.

If you're losing hair due to a medication, or your physician says it's safe to try hair loss treatments at the same time, it make make sense to consider FDA-approved hair loss treatments like minoxidil or finasteride. Both are clinically proven to help regrow hair, and both are available from Rex MD at affordable prices.