Isotretinoin
most data
The Dose Guy’s verdictSep 1, 20266 sources
The one drug that actually ends severe acne instead of managing it. I take it to look better, plainly. Nothing else comes close for cystic or treatment-resistant acne, and most people who finish a course stay clear. The trade is real: dryness everywhere, mandatory bloodwork for liver and lipids, genuine mood monitoring, and absolutely no pregnancy anywhere near it. That is the deal, and I think it is worth it if your skin is the problem.
What it is
A retinoid, a vitamin A derivative that shrinks the sebaceous glands, cuts sebum production to nearly nothing, and rewires the skin-cell turnover that clogs pores. Most acne drugs suppress symptoms while you take them. Isotretinoin runs a course, typically four to six months, and the acne stays gone for most people. It is a reset, not a management tool. That is why it works where everything else has failed.
About one in five people relapses, but only about 8% come back for another full course. Women relapse more often than men.
What the research shows
The efficacy is old, established, and not in doubt. The interesting recent work is about dose: conventional dosing clears acne no better than lower doses, and patients prefer the lower approach:
Realistic protocols
Start low and ride the dose you tolerate. The old dogma was to push toward a cumulative target of 120 to 150 mg/kg, but the cumulative-dose trial found no significant difference between the two, and low daily doses clear just as well with fewer side effects and higher satisfaction. A starting dose of 10 to 20 mg daily is sensible for most people. If you tolerate it well after a month, you can push toward 0.5 mg/kg/day, but there is no need to race to the top.
Take it with a fatty meal. Isotretinoin is fat-soluble, and absorption improves significantly with food.
Bloodwork: fasting lipids and liver enzymes at baseline, at one month, and every two to three months through the course. Triglycerides climb fastest. If lipids go sideways, dropping the dose usually brings them back.
Pregnancy is absolute. Isotretinoin causes severe birth defects. If pregnancy is possible, two forms of contraception and the iPLEDGE program are non-negotiable. This is not a suggestion.
Mood: the psychiatric signal is real. The largest observational study found no association with acute psychiatric hospitalization within two months, but the FAERS database holds 19,412 psychiatric adverse-event reports with a median onset of 80 days. That timeline lands in the middle of the course. Monitor mood through the entire treatment, not just the first month. If something shifts, act on it.
Daily life on isotretinoin: alcohol stacks with the triglyceride and liver-enzyme climb the labs are watching, so keep it minimal or cut it entirely. Your skin will burn faster. Wear high-SPF sunscreen and skip tanning. Do not wax, laser, or have cosmetic resurfacing during the course or for six months after, the skin is too fragile and will scar. Avoid vitamin A supplements and tetracycline antibiotics, both compound isotretinoin’s effects. You cannot donate blood while on isotretinoin or for one month after stopping.
Side effects
Dryness is the constant. Everything else is monitoring:
