Isotretinoin for Acne: Results, Dosing, Relapse, Side Effects and the Pregnancy Rules

Isotretinoin, widely known by the brand name Accutane, is the most effective acne treatment available, and the only one that can produce long-lasting remission of severe acne in many people. It is also one of the most tightly controlled medicines in the world, because it causes severe birth defects and needs blood tests and monitoring throughout the course.

This guide sets out what the evidence says about isotretinoin for acne: who it is for under current guidelines, how the dose and course are worked out, what results look like, how often acne comes back, the side effects and blood tests, the pregnancy rules, and what a 2024 meta-analysis of 1.6 million people found about mood and suicide. The numbers come from the US prescribing information, the 2024 American Academy of Dermatology (AAD) acne guideline and named studies.

The short answer

Isotretinoin is an oral vitamin A derivative taken for about 15 to 20 weeks. In the trial behind one US brand, about 7 in 10 people with severe nodular acne had cleared at least 90% of their nodules by week 20. The 2024 AAD guideline strongly recommends it for acne that is severe, causing scarring or psychosocial burden, or not responding to standard treatment. It must never be taken during pregnancy or by anyone who could become pregnant without strict contraception and pregnancy testing. It needs blood tests for lipids and liver function, and doctors monitor mood during treatment even though a large 2024 meta-analysis found no overall increase in suicide or psychiatric disorders.

What isotretinoin is and how it works

Isotretinoin is a retinoid, a close chemical relative of vitamin A. The prescribing information describes it as inhibiting the oil glands and the build-up of skin cells that blocks pores. Improvement goes along with a fall in oil production, which reflects the oil glands shrinking. The label says the fall in oil production is temporary, and the exact mechanism in acne is not fully known, so why the benefit often outlasts the course is not fully understood.

In the US, isotretinoin is sold as Absorica, Absorica LD, Amnesteem, Claravis and several generic capsules. Roche withdrew the original Accutane in the US in 2009, and the Accutane name is now back on a capsule from a different company (DailyMed lists a 2026 Accutane label from JG Pharma). Our generic Accutane guide covers the brands and the differences between them.

Who it is for

The US prescribing information limits isotretinoin to severe recalcitrant nodular acne in people aged 12 and over who are not pregnant: multiple inflamed nodules 5 mm or more across that have not responded to conventional treatment, including antibiotic tablets.

The 2024 AAD guideline is broader. It strongly recommends isotretinoin for acne that is:

• severe;
• causing scarring;
• causing psychosocial burden; or
• failing standard oral or topical treatment.

In practice, that means dermatologists now use it for moderate acne that keeps coming back after antibiotics, or that is leaving scars, not only for the most severe cases. Milder acne usually starts with topical retinoids, benzoyl peroxide and, if needed, a course of oral antibiotics. See our guides to using tretinoin and doxycycline for acne. Our guide to adapalene over the counter versus prescription covers what those first steps cost in the US.

The dose and how long a course lasts

Question	What the US prescribing information says
Daily dose	0.5 to 1 mg per kg of body weight per day (Absorica LD: 0.4 to 0.8 mg/kg)
How to take it	In two divided doses; swallow whole with a full glass of liquid
With food?	Standard capsules such as Amnesteem: with food. Absorica: with or without food
Course length	15 to 20 weeks; can stop early if nodules fall by more than 70%
Very severe acne or acne mainly on the trunk	Up to 2 mg/kg per day in adults, as tolerated
Second course	Not before a 2 month break, because acne can keep improving after stopping
Once daily dosing	Not established and not recommended

Food matters a lot for standard capsules. In the Amnesteem label, a high fat meal increased total exposure 2.7 times and peak levels 2.9 times compared with taking it fasting. That is why those capsules are taken with food. For Absorica, a high fat meal made no clinically significant difference, so it can be taken either way. Absorica and Absorica LD cannot be swapped for each other at the same dose.

Body weight	0.5 mg/kg per day	1 mg/kg per day
50 kg	25 mg	50 mg
60 kg	30 mg	60 mg
70 kg	35 mg	70 mg
80 kg	40 mg	80 mg
90 kg	45 mg	90 mg

Doses in the table are total daily amounts from the Absorica label, taken as two doses. Doctors usually start at the lower end and adjust by response and side effects.

What results to expect

The trial behind the Absorica approval enrolled 925 people aged 12 to 54 with severe nodular acne and at least 10 nodules, and compared Absorica with another isotretinoin capsule. By week 20:

Measure	Absorica (n=464)	Another isotretinoin capsule (n=461)
Average nodules at the start	18.4	17.7
Average reduction by week 20	15.68	15.62
90% or greater reduction in nodules	324 (70%)	344 (75%)

Both products took the average patient from about 18 nodules to about 2 or 3. The label adds that a single 15 to 20 week course has been shown to produce complete and prolonged remission in many patients. That is what sets isotretinoin apart: other treatments control acne while you use them, and it often goes away after the course ends.

The first weeks can be worse

Improvement is gradual. The prescribing information notes that a temporary flare of acne has been seen, generally early in treatment. Rarely, isotretinoin can trigger acne fulminans, a severe, painful, ulcerating form of acne, which the label lists among its reported reactions. Doctors sometimes start at a lower dose in people with very inflamed acne for this reason. A sudden severe worsening with fever, joint pain or open sores needs prompt medical review.

How often acne comes back

Isotretinoin does not guarantee permanent clearance. In a prospective study of 180 patients at one US centre, 116 answered a survey 12 months after finishing:

• 97.4% said their acne was better than before treatment.
• 32.7% had needed prescription acne treatment again within the year.
• Only 1.72% had needed a second course of isotretinoin.

Relapse was linked to the total dose received over the course:

Total dose over the course	Needed prescription acne treatment again within 12 months
Under 220 mg per kg	47.4% (95% CI 32.3% to 63.0%)
220 mg per kg or more	26.9% (95% CI 18.3% to 37.8%)

This was not a randomised trial. The doctors chose the doses, so other differences between the groups may explain part of the gap. It is one reason dermatologists often aim for a total dose rather than a fixed number of weeks. The conventional cumulative target is often given as 120 to 150 mg per kg, and some dermatologists go higher.

Low dose isotretinoin

Many dermatologists now use lower daily doses, especially for moderate acne, to reduce side effects. A 2026 meta-analysis of four randomised trials (202 patients analysed, mostly moderate acne) compared up to 0.5 mg/kg per day with 0.5 to 1 mg/kg per day. At 24 weeks there was no significant difference in acne scores, and the lower dose was better tolerated with higher patient satisfaction. The evidence was rated low certainty for effectiveness, and it says little about the most severe acne.

A 2022 meta-analysis of low daily doses in adults with mild to moderate acne was more cautious, finding that the conventional dose improved the odds of prolonged remission. The honest summary: lower doses are gentler and work well for many people with moderate acne, but the course may need to run longer to reach the same total, and relapse after low dose courses is less well studied.

Common side effects

Almost everyone on isotretinoin gets dryness. In the relapse study above, almost 100% of patients developed dry, cracked lips (cheilitis) and dry skin. The label notes that cheilitis and raised triglycerides are dose related. Other effects the label lists include:

• dry eyes, which can make contact lenses uncomfortable, and dry nose with nosebleeds;
• skin that is more fragile, more sensitive to the sun, and slower to heal;
• muscle and joint aches, especially with strenuous exercise;
• headache;
• hair thinning, which the label notes has persisted in some cases.

Most of these settle after the course ends. Lip balm, a gentle moisturiser, eye drops and sunscreen help. The prescribing information advises avoiding waxing and skin resurfacing such as dermabrasion or laser during treatment and for at least 6 months afterwards, because of the risk of scarring, and avoiding prolonged sun or UV exposure.

Blood tests and why they matter

The label requires a fasting lipid profile and liver function tests before starting, then repeat tests until the response is known, which usually happens within 4 weeks for lipids.

Finding in clinical trials	How often
Marked rise in triglycerides	25%
Muscle enzyme (CPK) of 350 U/L or more, in a 924 patient trial	About 24%
Fall in HDL cholesterol	15%
Mild to moderate rise in liver enzymes	About 15%
Rise in total cholesterol	7%

The lipid changes reversed after stopping. Triglycerides above 800 mg/dL have been reported, and acute pancreatitis, rarely fatal, has occurred with isotretinoin. Weight loss and less dietary fat and alcohol can bring triglycerides down while treatment continues, or the dose can be lowered. The label advises waiting 36 hours after drinking alcohol before a lipid test. People with diabetes, obesity, heavy drinking or a family history of lipid problems need closer monitoring.

Pregnancy: the rule with no exceptions

Isotretinoin carries a boxed warning. The prescribing information states there is an extremely high risk of life-threatening birth defects if pregnancy occurs while taking any amount, even for a short time, and that there is no accurate way to tell before birth whether a baby has been affected. Miscarriage, premature birth and reduced IQ in exposed children have also been reported.

Anyone who can become pregnant must, under the US label:

• have two negative pregnancy tests before starting, the second after at least 30 days of contraception;
• use two forms of contraception at the same time, at least one of them a primary method (such as an IUD, implant, combined pill, injection, sterilisation or a vasectomised partner), from 1 month before, throughout, and for 1 month after treatment, unless committed to continuous abstinence;
• have a pregnancy test before each monthly prescription, at the end of the course and 1 month after stopping.

Progestogen-only "minipills" are not an adequate method on their own. If unprotected sex happens at any point from a month before to a month after treatment, the label says to stop isotretinoin immediately and follow the retesting steps. Nobody on isotretinoin should donate blood during treatment or for 1 month after, because the blood could reach a pregnant patient.

The contraception and testing requirements continue until 1 month after the last dose. In men, the label reports no significant effects on sperm count or quality in the studies it describes, and the pregnancy prevention requirements apply to people who can become pregnant.

The iPLEDGE programme

Because of the birth defect risk, every isotretinoin product in the US is available only through a restricted programme called iPLEDGE. Prescribers, pharmacies, wholesalers and patients all have to be registered. Pharmacies can dispense no more than a 30 day supply at a time, with no refills, and patients who can become pregnant must collect each prescription within 7 days of their pregnancy test. Patients who cannot become pregnant still register and agree not to share the medicine or donate blood.

Outside the US, most countries run their own pregnancy prevention programmes. We state it plainly: taking isotretinoin outside a supervised programme, without pregnancy testing and blood tests, is not safe, and for anyone who could become pregnant it is dangerous.

Mood, depression and suicide: what the evidence shows

The prescribing information warns that isotretinoin may cause depression, psychosis and, rarely, suicidal thoughts, suicide attempts, suicide and aggressive behaviour. It asks doctors to ask about psychiatric history before starting and to check mood at each visit, and tells patients to stop and contact their doctor if depression or mood changes develop.

A 2024 meta-analysis in JAMA Dermatology pooled 24 studies with more than 1.6 million people. Each result below comes from the subset of studies that measured it: the suicide attempt figures from 2 studies with about 450,000 people, and the psychiatric disorder figure from 4 studies with about 59,000 people.

Outcome	Result
1 year absolute risk of completed suicide, suicide attempt, suicidal thoughts and self-harm	Each under 0.5%
1 year absolute risk of depression	3.83% (95% CI 2.45% to 5.93%)
Suicide attempt at 2 years, users against non-users	Relative risk 0.92 (0.84 to 1.00)
Suicide attempt at 3 years	Relative risk 0.86 (0.77 to 0.95)
Suicide attempt at 4 years	Relative risk 0.85 (0.72 to 1.00)
Any psychiatric disorder	Relative risk 1.08 (0.99 to 1.19), not significant

At a population level, isotretinoin users did not have a higher risk of suicide or psychiatric disorders, and had a lower risk of suicide attempts 3 years after treatment. During treatment and in the first year after it, the estimates for suicide attempts showed no clear difference either way, but they were imprecise. Severe acne itself harms mood, and clearing it may help. But population averages cannot rule out rare individual reactions, which is why the label's monitoring still applies. Anyone with low mood, anxiety, irritability or thoughts of self-harm during treatment should stop and speak to their doctor promptly. Families should know what to watch for.

Serious but rare side effects

The prescribing information lists these, each of which means stopping and getting medical advice:

• Raised pressure around the brain (intracranial hypertension): severe headache, nausea, vomiting or blurred vision. Some cases involved tetracycline antibiotics such as doxycycline, which should not be taken at the same time.
• Pancreatitis: severe abdominal pain.
• Inflammatory bowel disease: abdominal pain, rectal bleeding or severe diarrhoea.
• Liver inflammation: yellowing skin or eyes, dark urine.
• Serious skin reactions: blistering rash or peeling skin.
• Vision and hearing changes: including reduced night vision, which may persist, and ringing in the ears or hearing loss.

Teenagers, bones and sport

Isotretinoin is approved from age 12. The label reports that 9% of adolescents (27 of 306) in one trial had a clinically significant drop in bone mineral density (4% or more at the spine or hip, or 5% or more at the femoral neck) during a 20 week course, and back pain in about 29% of adolescents in another trial, severe in 14% of those cases. It also notes early closure of growth plates, a higher risk of spinal stress injuries (spondylolisthesis, with or without fractures of the pars) in teenagers who play sports with repetitive impact, and reports of hip growth plate injuries. Second courses are generally for people who have finished growing. None of this rules isotretinoin out for teenagers, but it is part of the discussion with the prescriber.

Medicines and supplements to avoid

• Vitamin A supplements: isotretinoin is closely related to vitamin A, and the combination adds to side effects.
• Tetracycline antibiotics (doxycycline, minocycline, tetracycline): linked to raised pressure around the brain.
• Hormonal contraception: the label found no significant interaction with a norethindrone and ethinyl estradiol pill, and says interactions with other oral contraceptives are not known. Two methods are required because any single method can fail.
• Alcohol: adds to the rise in triglycerides.

Alternatives if isotretinoin is not right for you

The 2024 AAD guideline strongly recommends benzoyl peroxide, topical retinoids, topical antibiotics and oral doxycycline, and gives conditional recommendations for others, including combined oral contraceptives and spironolactone in women, and azelaic acid. Combining topical treatments with different actions, and limiting antibiotic courses, are good practice. See our guides to topical antibiotics for acne, azelaic acid and adapalene versus tretinoin, and our tretinoin results timeline. Dapsone gel, another topical prescription option, has its own dapsone gel 5% and 7.5% guide.

When to see a doctor

Isotretinoin should only be taken under a doctor who can arrange the pregnancy testing, blood tests and follow-up it requires. During a course, contact your doctor promptly about low mood or thoughts of self-harm, severe headache or blurred vision, severe abdominal pain, rectal bleeding, yellowing of the skin, a blistering rash, or any chance of pregnancy. Our acne page covers the full range of treatments.

Sources

• ABSORICA and ABSORICA LD (isotretinoin) US prescribing information, including boxed warning and sections 1, 2, 5, 6, 7, 8 and 14. DailyMed
• AMNESTEEM (isotretinoin) US prescribing information, sections 2 and 12.3. DailyMed
• Reynolds RV et al. Guidelines of care for the management of acne vulgaris. J Am Acad Dermatol 2024;90(5):1006.e1-1006.e30. PMID 38300170.
• Blasiak RC et al. High-dose isotretinoin treatment and the rate of retrial, relapse, and adverse effects in patients with acne vulgaris. JAMA Dermatol 2013;149(12):1392-8. PMID 24173086.
• Tan NKW et al. Risk of suicide and psychiatric disorders among isotretinoin users: a meta-analysis. JAMA Dermatol 2024;160(1):54-62. PMID 38019562.
• Zou J et al. Individualizing isotretinoin dosing in acne: comparable 24-week efficacy and better tolerability at lower daily doses. Front Med 2026;13:1771320. PMID 41877774.
• Al Muqarrab F, Almohssen A. Low-dose oral isotretinoin for the treatment of adult patients with mild-to-moderate acne vulgaris: systematic review and meta-analysis. Dermatol Ther 2022;35(4):e15311. PMID 35000295.

This article is for information only and is not medical advice. Isotretinoin is a prescription medicine that causes severe birth defects and must only be used under medical supervision with the required pregnancy prevention and monitoring.