Acitretin

What it is

Acitretin is an oral retinoid, the active metabolite of the older drug etretinate, used for severe psoriasis and related skin disorders. It is prescription-only in the US, EU and UK. It is not a hair treatment; any hair effect is a side effect. Katz 1999

How it works

Retinoids change how skin cells grow and mature. Hair loss from retinoids is thought to be telogen effluvium, shedding of resting hairs that shows about 2 to 4 months after the trigger. The detailed mechanism is not established. Tosi 1994

What the studies show

• The US label lists alopecia in its 50% to 75% frequency band among 525 trial subjects, alongside skin peeling. Abnormal hair texture and hair discoloration are in the less frequent list. US label
• A pooled analysis of two pivotal trials found common side effects, including alopecia, were 2 to 3 times more frequent at 50 mg/day than at 25 mg/day. Pearce 2006
• A review called cheilitis and hair loss the most common dose-dependent side effects, sometimes needing a lower dose. Katz 1999
• Case report: a 70-year-old woman's white hair darkened and became curly after 6 months of acitretin. Seckin 2009

Retinoid-induced shedding generally recovers after stopping, but this was not quantified for acitretin in the sources we read.

How it's used in studies

Trials compared 25 mg/day with 50 mg/day.

Side effects and safety

• Pregnancy: the US label says acitretin must not be used by anyone who is pregnant, intends to become pregnant during treatment or in the 3 years after stopping, or cannot use reliable contraception in that period. Major fetal abnormalities have been reported.
• Alcohol can lead to formation of etretinate, which clears far more slowly, hence the long 3-year window.
• Other effects include dry lips, skin and eyes, raised liver enzymes and lipids, and rarely pancreatitis.
• Do not add vitamin A or hair supplements that contain it; check any hair blend (hair supplement blends).
• In the UK, oral retinoids are prescribed within specialist teams under a Pregnancy Prevention Programme. MHRA

Bottom line

Thinning is likely and dose-related, so ask the prescriber about the lowest effective dose. It is a trade-off against psoriasis control, not something a supplement fixes. No hair supplement has trial evidence alongside acitretin. Pregnancy and alcohol rules are the dominant safety message. Discuss with a doctor.

Fun facts

• Acitretin turned one woman's white hair dark and curly. Seckin 2009