Isotretinoin
Sounds like 'iso-tret-in-noin'
Key points about isotretinoin
- Isotretinoin is used to treat severe acne.
- Isotretinoin can cause severe birth defects in pregnant people. Don't take isotretinoin if you are pregnant, or if there is a chance you could become pregnant. You may be asked to sign a consent form to make sure you have understood the seriousness of this.
- Find out how to take isotretinoin safely and possible side effects.

Isotretinoin is used to treat severe acne that is not getting better with other treatments. It reduces the amount of oil made by the glands in your skin and shrinks the oil-producing glands (sebaceous glands). It also inhibits the growth of bacteria and reduces pore clogging, redness and inflammation.
Isotretinoin is an effective treatment for acne. About 9 out of 10 people treated with isotretinoin see a significant improvement in their acne after a single course of isotretinoin, although during the first few weeks of treatment the acne may worsen before it starts to improve.
Note: Isotretinoin can cause serious side effects such as severe birth defects in pregnant people, low mood and behaviour problems and liver problems. For more detailed information, see below: Things to consider before you start isotretinoin and What to know while you're taking isotretinoin.
In Aotearoa New Zealand isotretinoin is available as capsules in different strengths (5 mg, 10 mg and 20 mg).
- The usual dose of isotretinoin is 10 mg or 20 mg once a day until your acne has cleared (usually 3 to 5 months but it can take up to 18 months).
- Your doctor will then reduce your dose for a further 2 to 4 months to avoid the acne coming back and scarring.
- Always take your isotretinoin exactly as your doctor has told you. The pharmacy label on your medicine will tell you how much to take, how often to take it, and any special instructions.
- Timing: Take isotretinoin once a day, at about the same time each day. Isotretinoin is best taken with or just after food. Swallow the capsules whole with a glass of water. Don't split or chew them.
- Missed dose: If you forget to take your dose, take it as soon as you remember. But, if it's nearly time for your next dose, just take the next dose at the right time. Don't take double the dose.
Don't take isotretinoin if you're pregnant, or there's is a chance you could become pregnant.
- Before you start treatment, your doctor may arrange a pregnancy test to make sure you're not pregnant.
- If you're sexually active, ask your doctor about reliable contraceptive options. You must use reliable birth control for at least 1 month before you start isotretinoin, while you are taking isotretinoin and for at least 1 month after you finish taking it. Read more about methods of contraception.
- You may be asked to sign a consent form to make sure you have understood the seriousness of this, eg, Isotretinoin consent form(external link).
- Note: No contraceptive precautions are required for males who are taking isotretinoin; birth defects have not been identified in children fathered by men who have taken isotretinoin.
Dry skin, lips, nostrils and eyes
Because isotretinoin reduces oil production in the skin, it can cause dry skin, dry mouth, chapped lips, dry nostrils and dry eyes. These effects can be uncomfortable. Here are some tips to manage them, but if you have any questions, ask your doctor or pharmacist for advice.
- Lips: From the start of treatment, use an emollient lip balm that has a sunscreen. It's important to apply the lip balm often during the day, such as in the morning as soon as you wake up, after any food, snack or drink, last thing at night and any other time in between that your lips become dry.
- Skin: From the start of treatment, use a non-perfumed moisturizing cream. Use non-soap cleansers, as these are less likely to irritate the skin, compared with a soap cleanser. Avoid beauty treatments such as chemical peels, dermabrasion and waxing during treatment and for at least 6 months after stopping.
- Eyes: Your eyes may become dry and itchy, especially if you wear contact lenses. Ask your pharmacist to recommend a suitable eye lubricant (also called artificial tears). Read more about eye lubricants. While you're taking isotretinoin, you may need to wear glasses instead of contact lenses.
- Nostrils: The inside of the nostrils may become dry and crusted and lead to mild nose bleeds. Applying a thin layer of petroleum jelly gently to the inside of your nose may help.
Increased sensitivity to the sun
Isotretinoin can make you more sensitive to the sun and your skin is more likely to burn.
- Avoid unnecessary sun exposure.
- When you're outside, protect your skin by using an oil-free sunscreen (SPF50+). Apply the sunscreen to all areas especially the face, neck and ears. Read more about using sunscreen.
- Wear clothing that protects you from the sun.
- Wear sunglasses when outdoors.
Avoid waxing for hair removal
Waxing can cause permanent scars in people taking isotretinoin. To avoid scarring, you mustn't wax while taking isotretinoin and for 6 months after you stop taking isotretinoin. This applies to hot wax and cold wax.
Changes in mood and behaviour
There have been reports of depression, low mood and behaviour changes from some people taking isotretinoin, although it hasn't been confirmed that isotretinoin was the cause. Special care is needed if you have a history of depression. Contact your doctor immediately if you experience any changes in your mood, become withdrawn, have distressing thoughts, or feelings about suicide or harming yourself, or you're feeling sad, anxious, worthless or hopeless.
Night vision may be affected
Night vision may be affected by isotretinoin. Good night vision is important for airline pilots and those flying after dark. Pilots taking isotretinoin or considering a course of isotretinoin must report to their national aviation authority to discuss how this treatment affects their flying privileges.
In Aotearoa New Zealand, this is the Civil Aviation Authority of New Zealand(external link) (CAA). Civil aviation licence holders, including Air Traffic Controllers, need to tell the CAA they are taking isotretinoin as this may affect flight safety. CAA considers the use of isotretinoin to be a change in medical condition.
Taking other medicines
Isotretinoin interacts with a few medicines such as some antibiotics and vitamin A products, including multivitamins. Check with your healthcare provider before taking any other medicines or supplements.
Breastfeeding
Don't take isotretinoin if you're breastfeeding.
Donating blood
Donating blood isn't allowed during treatment with isotretinoin, and for 4 weeks after treatment has finished. This is in case the blood is used for a pregnant woman.
Like all medicines, isotretinoin can cause side effects, although not everyone gets them. Often side effects improve as your body gets used to the new medicine.
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Read more about medicines and side effects and reporting a reaction you think might be a side effect.
Isotretinoin (capsule)(external link) New Zealand Formulary
Oratane(external link) Consumer information sheet, Medsafe NZ
Isotretinoin(external link) DermNet NZ
Resources
Isotretinoin(external link) Patient guide SafeRx, Waitematā DHB, NZ, 2011
5 questions to ask about your medications(external link) Health Quality and Safety Commission, NZ English(external link), te reo Māori(external link)
References
- Prescribing isotretinoin for patients with acne in primary care(external link) BPAC, NZ, 2017
- Isotretinoin(external link) DermNet NZ
- Isotretinoin (systemic)(external link) New Zealand Formulary
- Isotretinoin(external link) British Association of Dermatologists, UK, 2022
Brochures
Patient guide SafeRx, Waitematā DHB, NZ, 2011
Medicines and side effects
Healthify He Puna Waiora, NZ, 2024
Health Quality and Safety Commission, NZ, 2019
English(external link)Te reo Māori(external link)
Credits: Sandra Ponen, Pharmacist, Healthify He Puna Waiora. Healthify is brought to you by Health Navigator Charitable Trust.
Reviewed by: Angela Lambie, Pharmacist, Auckland
Last reviewed: