Does Otrexup Cause Hair Loss?
Otrexup, an autoinjector form of methotrexate used for rheumatoid arthritis, psoriasis, and polyarticular juvenile idiopathic arthritis, lists alopecia (hair loss) as a possible side effect. This stems from methotrexate's mechanism, which inhibits folate metabolism and can disrupt rapidly dividing cells like hair follicles. Clinical data shows alopecia in up to 3% of patients on methotrexate, though rates vary by dose and duration—higher with oral or high-dose regimens, less common with subcutaneous Otrexup.[1][2]
How Common Is Hair Loss with Otrexup?
Hair loss occurs infrequently. In rheumatoid arthritis trials for subcutaneous methotrexate (Otrexup's active ingredient), alopecia affected 1-3% of patients, often mild and reversible upon dose reduction or folic acid supplementation. Patient reports on forums like Drugs.com note thinning rather than baldness, typically after months of use.[3][4]
Why Does Methotrexate in Otrexup Trigger Hair Loss?
Methotrexate slows cell growth by blocking dihydrofolate reductase, impacting hair follicle cycles. Subcutaneous delivery like Otrexup may reduce gastrointestinal side effects but doesn't eliminate this risk. Factors increasing likelihood include high weekly doses (>15 mg), long-term use, and concurrent drugs like leflunomide.[1][5]
Can You Prevent or Reverse Otrexup-Related Hair Loss?
Folic acid (1-5 mg daily) supplements mitigate many methotrexate side effects, including alopecia, by countering folate depletion—standard in prescribing guidelines. Hair often regrows after lowering dose, switching to alternatives, or stopping treatment. Consult a doctor before changes; abrupt stops risk disease flare.[2][6]
What Do Patients Report about Hair Loss?
Real-world experiences vary: some describe diffuse thinning after 6-12 months, others none even after years. Reddit and patient review sites highlight it as less severe than with oral methotrexate due to better tolerability. Women report it more often, possibly tied to hormonal factors.[4][7]
Alternatives to Otrexup If Hair Loss Is a Concern