Methotrexate Hair Shedding: Causes, Timeline & Practical Steps

Noticing more hair in the shower or on your brush after starting methotrexate? That can happen. Methotrexate sometimes pushes hair into a resting phase so strands fall out more easily. The good news: most cases are temporary and manageable.

Why methotrexate causes hair shedding

Methotrexate interferes with rapidly dividing cells. Hair follicles are sensitive to that, so some hairs stop growing and enter telogen (resting) phase. This type of shedding usually shows up weeks to a few months after starting treatment or after a dose change. Higher doses—like those used in cancer—cause more obvious loss. Low-dose methotrexate for autoimmune conditions can still cause thinning, but it’s often milder.

Other things can add up: iron deficiency, thyroid problems, stress, and other meds can make shedding worse. A dermatologist or your prescriber will often call this drug-induced telogen effluvium when they see the pattern.

What to do right now

Don’t stop methotrexate on your own. Stopping suddenly can flare your disease. Instead, call the doctor who prescribed it and describe what you’re seeing. They may check basic labs (CBC, iron/ferritin, TSH, vitamin D, B12) and consider a dose change or switching therapies if the hair loss is severe.

Practical care you can start today: switch to a gentle shampoo, avoid tight hairstyles and heated tools, and use a wide-tooth comb. These steps reduce breakage and make shedding less obvious. If you want active treatment, topical minoxidil often helps speed regrowth for drug-related thinning. Ask your dermatologist if it’s right for you.

For stubborn cases, dermatologists may offer platelet-rich plasma (PRP) or other treatments once the medication and labs are stable. Hair transplant is only considered later, when hair has stopped changing for many months.

If you’re pregnant or planning pregnancy, mention methotrexate immediately—this drug can cause birth defects and needs careful management. Also seek urgent care if you see rapid patchy loss, scaly or painful scalp, or signs of infection. Those signs suggest a different problem that needs prompt treatment.

Expect regrowth to take time. If methotrexate is the cause, hair often begins to recover within 3–6 months after dose reduction or stopping the drug, and fuller regrowth can take longer. Track changes with photos every month so you and your clinician can see progress.

Final quick checklist: don’t stop medication without advice, get basic blood tests, protect your hair from damage, discuss topical minoxidil or dermatologist referral, and report scary symptoms right away. Small steps now can make regrowth easier later.