Which drugs & medications cause hair loss?

Top Items with the Strongest Evidence about Drug- and Toxin-Induced Alopecia

1) Heavy metals & classic toxicants

• According to the article Alopecia and Associated Toxic Agents: A Systematic Review published in 2018, thallium is a well-documented cause of anagen effluvium along with systemic toxicity (gastrointestinal, neuropathy, Mees lines). 
• Based on a medical article published in the National Library of Medicine titled Anagen Effluvium Following Acute Colchicine Poisoning, colchicine is a medication used to treat gout, familial Mediterranean fever (FMF) and certain other types of inflammation. However, it inhibits microtubule formation, causing disruption to the intracellular cytoskeletal structure. Consequently, taking excessive or toxic doses can lead to anagen effluvium, which is a sudden form of permanent hair loss caused by the interruption of active follicle production.
• Selenium is an essential trace mineral, which is why it is commonly found in multivitamin supplements. However, taking excessive amounts or taking supplements with incorrect dosages can lead to widespread hair loss. According to the Human and Experimental Toxicology, the ideal daily intake of selenium for adults is generally 55 micrograms (µg). Intakes above 400 µg a day can lead to selenosis, which is associated with loss of hair and nails and neurological disturbances. As the Perseus Vitamin formulation does not include selenium, we promote hair health by incorporating alternative nutrients, such as silica from horsetail extract, zinc, biotin and vitamins B3, B5 and B6, to support strong and thick hair.
• In addition to above, mercury, arsenic, and boric acid are other substances that cause hair loss due to toxic exposure.

2) Prescription drugs and medical treatments related to hair loss

The section above presented naturally occurring substances that trigger hair loss. This section focuses on medications and treatments developed by humans that can also result in hair loss.

• Chemotherapy-induced hair loss: Hair falls begins within 14 to 28 days after starting chemo treatment. Don’t panic, hair usually starts to grow back 6-8 weeks after completing your cancer treatment.
• Warfarin & Heparin and Hair Shedding: Loss of hair strands may begin 2 to 3 months after starting anticoagulant therapy. These drugs can induce telogen effluvium.
• Beta-Blockers: Hair loss associated beta-blockers can occur 60 to 90 days following treatment. No need to worry because hair loss due to beta-blockers are temporary and hair begins to regrow after 4-5 months of treatment.
• Antidepressants (SSRIs/SNRIs): Depending on the type of antidepressant, hair loss can begin anywhere from 3 days to years later. Studies indicate that it typically begins after an average of 8.5 weeks. The hair loss follows a pattern similar to telogen effluvium.
• Antibiotics: Hair loss from antibiotic use begins within 2-3 months. It causes hair loss by altering the hair growth cycle.
• Thyroid medications like Levothyroxine: Some articles claim that hair loss increases when starting thyroid treatment. However, it is said that this is temporary hair loss.
• Oral contraceptives: Hair shedding due to oral contraceptives often begins 2 to 3 months after starting the medication, as the hormonal changes caused by the contraceptives can lead to telogen effluvium.

3) Recreational Synthetic Drugs and Unusual Agents

• MT-45 (synthetic opioid): Emerging case reports describe hair loss, skin, and eye effects in individuals exposed to or abusing MT-45. Evidence is limited and primarily observational. 
• Podostroma cornu-damae (toxic mushroom): Poisoning cases have documented hair loss among other systemic toxic effects. Evidence is restricted to case reports and small case series.
• Botulinum Toxin A: Although it is widely used for cosmetic purposes, there are very few reported cases of localized eyebrow or eyelash loss following injection.

Attention please! These substances are toxic and can cause serious health issues including hair loss. All references are for educational purposes; do not attempt use.

4) What You Can Do to Prevent Hair Loss due to Drugs & Treatments?

• Read the ingredients: Take a look at the ingredients section of the product you purchased. 
• Review medications and supplements: Keep a timeline of new drugs or dosage changes.
• Consult your doctor: A clinician can evaluate your hair loss pattern, order lab tests (including toxicology if needed), and adjust medications.
• Track hair changes: Take photos of your scalp weekly or monthly to notice subtle changes early.
• Gentle hair care: Avoid harsh chemical treatments, tight hairstyles, or excessive heat styling during recovery.