Post-Accutane syndrome (PAS)

Post-Accutane syndrome (PAS) is a condition caused by isotretinoin, a medicine for severe acne. It can affect mental health, sexual function, cognition and the body. Symptoms can start during treatment or only after it, and can last for years. Its UK brand is Roaccutane; Accutane was its US brand.

PAS has no official definition. Only its sexual form has published diagnostic criteria.

PAS is one of three related conditions, with PFS (after finasteride) and PSSD (after SSRI and SNRI antidepressants). The 2022 criteria cover all three.

The 2022 diagnostic criteria

There is no blood test or scan for PAS. In 2022, 37 doctors and researchers from ten countries agreed diagnostic criteria for its sexual form, which they call post-retinoid sexual dysfunction (PRSD).

• Required: you took isotretinoin.
• Required: sexual problems continued after you stopped.
• Supporting: lasting loss of desire, erection problems or less vaginal lubrication, less feeling in the genitals and at orgasm, and problems that have lasted 3 months or more.
• Ruled out: the same problems before the medicine, or another illness, medicine or drug use that explains them. The criteria also ask for no earlier finasteride or SSRI-type antidepressant (see PFS and PSSD).

A current mental health diagnosis does not rule it out. The paper adds that the name PAS is also used for mental health and cognitive problems “without sexual difficulties”. The criteria do not cover those.

The criteria are an expert consensus, not official guidance. They were built from cases reported to RxISK.org, a drug safety website linked to three of the authors.

The medicine, its names and codes

The criteria need a sexual problem for a diagnosis. The other groups can come with it, or on their own.

The sexual group comes from the 2022 criteria and the UK prescribing information. The criteria add the mental health, cognitive, skin, joint and bowel changes. The label adds anxiety and mood changes, and says poorer night vision has “in rare instances” persisted.

What the UK label says

The UK label reports “long-lasting sexual dysfunction” that continued after stopping. On mental health, it warns that stopping “may be insufficient to alleviate symptoms”.

These numbers come from people who chose to report, and some gave their age years after treatment, the MHRA’s expert review notes.

Nobody has measured it; the criteria’s authors call the incidence “unknown”. In 2017, with about 30,000 UK patients a year, the MHRA said “the exact incidence of these adverse reactions is unknown”, though it judged reports rare.

Reports and their limits

• By May 2021 the MHRA had 184 Yellow Card reports of sexual side effects. It says the true number is “likely to be higher”, because the problem is “highly personal and a cause of embarrassment”.
• In 2024 Health Canada found 111 cases, 11 in Canada and 100 elsewhere. In just over half of the reported events, problems lasted “months to years” after stopping.
• Reports show that something happens, never how often. The FDA says its own database “cannot be used to calculate the incidence” of a side effect.

Why there is no rate

The original trials ran mainly in the early 1980s. Their recording of side effects was not “systematic or robust”, the MHRA’s experts found. Trials usually do not follow up sexual side effects after people stop, the criteria’s authors add.

A study following people from first dose to years after the last would answer the question. In 2023 the MHRA’s experts recommended a registry to record side effects “during and after treatment”.

Regulators in the UK, the EU and the US have added warnings and tightened prescribing, but none has recognised PAS as a condition. The UK’s experts concluded in 2023 that for severe acne the benefits “continue to outweigh the risks”.

United Kingdom

European Union

We have not found an EU-wide warning that sexual problems can continue after stopping. The Irish label we checked (February 2025) says only that some side effects “may persist”.

United States

In 2024 Health Canada concluded that a link, including to problems that continue after stopping, “could not be ruled out”.

If you are struggling, call Samaritans on 116 123 in the UK (free, any hour) or 988 in the US.

Research on lasting effects is thin. The MHRA’s experts called the literature on sexual side effects “not extensive”, and the FDA found no “adequately designed placebo-controlled studies”.

Sexual side effects

Mental health

The US label says isotretinoin “may cause depression, psychosis and, rarely, suicidal ideation, suicide attempts, suicide, and aggressive and/or violent behaviors”. Whether it does is still disputed, and studies point in different directions.

How it might happen

Nobody knows. Isotretinoin has actions similar to both SSRIs and finasteride, but “it is not clear whether the problem stems from either”, the criteria’s authors say.

Lasting epigenetic changes (in how genes are switched on and off) have been proposed, but whether they happen “is unknown”, the MHRA’s experts note. Our interview with Doug Bremner looks at brain research on isotretinoin.

There is no test for PAS. A doctor diagnoses it from your history, using the 2022 criteria for sexual symptoms. For other symptoms on their own the criteria do not apply, and diagnosis rests on ruling out other causes.

Your doctor may not have come across it. Most health professionals who answered the MHRA’s call for information “had not seen sexual side effects with isotretinoin”, though several “did not usually ask about it”. Since October 2023, UK prescribers have been told to ask.

What to bring to your doctor

• When you took isotretinoin, the dose if you know it, and when you stopped.
• When each symptom began: during the course, or after it.
• What things were like before you started.
• Every other medicine, before or since, including antidepressants and finasteride.
• In the UK, if you were treated after October 2023, your copy of the Acknowledgement of Risk Form.
• The criteria paper and the UK patient leaflet, both free to read.

Ruling out other causes

Sexual problems are common, and depression, anxiety and their treatments affect sex too, so a doctor will look for other causes. That is not dismissal: the criteria say a mental health diagnosis “does not prevent” diagnosis, and borderline hormone levels “may be a consequence of the conditions rather than a cause”.

There is no approved treatment for PAS. In September 2026 we found no treatment trial for it on ClinicalTrials.gov. A 2025 paper notes that the cause “is unknown, nor is an effective treatment available”.

Is PAS permanent?

It can be. Some people improve and some do not. Its sexual form “can remain for months, years or indefinitely”, the criteria say, and how many recover “has never been properly investigated”.

• About half of those reporting low sexual desire said it did not improve on stopping. Some reports describe problems lasting up to 24 years.
• Joseph says his symptoms have improved in a meaningful way with time, patience and support. He is clear that this is not a cure.

How to judge a treatment offer

You may come across treatments offered online or in private clinics. We do not recommend any. These questions help you and your doctor weigh an offer:

• Has it been tested in people with PAS, and where were the results published?
• Was there a comparison group? Without one, improvement may be time, not the treatment.
• What are its side effects, and what happens if it does not work?
• What does it cost, and does the person recommending it also sell it?
• Does your doctor know? Tell them before you start anything new.

SIDEfxHUB is a UK patient charity (registered charity 1203385) for people living with PFS, PSSD and PAS. We fund research, push for these conditions to be recognised, and support patients.

• The registry. Our registry follows people over months and years. Its members chose to join, so it cannot say how common PAS is. It can show patterns: which symptoms, when they began and how they change.
• Research. We raise money for the Milano Project at the University of Milan, which studies finasteride and SSRIs, not isotretinoin. In our view the evidence gap is widest for PAS, which is why we want people with PAS in the registry.

Every source below was checked on 26 September 2026.