Methotrexate can sometimes lead to hair loss or thinning. It’s uncommon, but some things can help prevent it.
You may have heard of methotrexate. Doctors prescribe high doses to treat certain cancers. People often experience some side effects when it’s used to treat cancer, such as hair loss, stomach issues, and mouth ulcers.
You can experience similar side effects when taking much lower doses for chronic conditions, including rheumatoid arthritis (RA), psoriatic arthritis (PsA), and psoriasis (PsO). Still, hair loss isn’t a common side effect at these lower doses and is often temporary and mild.
You may also be able to take some steps to help prevent hair loss associated with methotrexate.
Methotrexate is a disease-modifying antirheumatic drug (DMARD). Doctors often prescribe low doses for the treatment of certain chronic conditions, including RA, PsA, and PsO. In fact, it’s the most commonly prescribed DMARD for RA.
When doctors prescribe methotrexate for these chronic conditions, the dose often ranges from 15 milligrams (mg) to 25 mg per week. At much higher doses, methotrexate helps treat some types of cancer, like leukemia.
Methotrexate is a folate antagonist or blocker. Folate is one type of B vitamin that cancer cells use to help rapidly grow and multiply. Your body also needs folate to function as it should, and many cells — like hair follicles — require the nutrient.
Methotrexate’s folate-blocking properties don’t help with treatment for RA, PsA, or PsO. Instead, research suggests that methotrexate may slow progression and relieve symptoms associated with these inflammatory conditions by triggering cells to release a substance called adenosine.
Adenosine blocks other substances that trigger or cause inflammation in the body.
For some people taking methotrexate for RA, PsA, or PsO, mild hair loss can occur as a side effect of the folate-blocking properties of the medication.
People respond to medications differently, which means not everyone experiences side effects like hair loss when taking methotrexate.
The Arthritis Foundation suggests that about 1–3% of people taking methotrexate experience mild hair loss.
Some evidence suggests that hair loss due to taking methotrexate may occur much more frequently.
According to a 2019 study, researchers discovered that hair loss — particularly among females — occurred at a rate of 29.4%. This suggests that hair loss as a side effect of the medication may be common, but their sample size consisted of 68 people, making it difficult to generalize the findings.
Hair loss is typically gradual. If you experience hair loss due to methotrexate, you’ll likely not lose patches of hair. Instead, it may gradually thin over time.
When a doctor prescribes methotrexate, they may also prescribe folic acid supplements. Replacing folic acid in the body may help prevent further hair loss and other common side effects of methotrexate, such as mouth ulcers or stomach upset.
How and when a doctor suggests to take folic acid may vary. Some common dosages and time frames include:
Splitting the dose of methotrexate or switching to injections may help as well.
If you experience other side effects, like nausea or mouth sores, taking anti-nausea medications, such as ondansetron (Zofran), or using a mouthwash with lidocaine may help.
If you stop using methotrexate, you should notice your hair starts to grow back and thicken. Taking folic acid during treatment may help prevent hair loss and other side effects.
Methotrexate may make hair thinner. It can deprive hair follicles of folate, which weakens hair and promotes faster loss.
Some evidence suggests that methotrexate may help treat certain types of hair loss. People living with alopecia totalis may experience hair loss. Methotrexate helps slow or stop the overactive immune system response, which may help with preventing hair loss.
According to a 2018 study, methotrexate alone may not help treat and prevent hair loss. Instead, it may help when used in combination with systemic corticosteroids. Further studies should examine the effectiveness of using methotrexate for hair loss in people living with alopecia totalis.
Hair loss and thinning can occur when taking lower doses of methotrexate for certain chronic conditions. This side effect is uncommon, and if it does occur, it’s usually temporary and mild.
You’ll likely not experience significant loss or loss in clumps. If you do, you may want to consider talking with a doctor about your hair loss. It may indicate another underlying issue that may require treatment.
You may also want to discuss taking folic acid with a doctor. Folic acid may help alleviate side effects like hair loss, mouth sores, or stomach symptoms when using methotrexate.
Medically reviewed on November 20, 2023
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