What Blood Tests Are Needed on Isotretinoin?

Isotretinoin needs liver function tests and fasting blood fat (lipid) tests. The product information advises checking them before treatment, one month after starting, then every three months unless more frequent checks are needed. Anyone who could become pregnant also needs medically supervised pregnancy tests before, during and after treatment.

Blood tests are only one part of isotretinoin monitoring. Regular reviews also check how your acne is responding, any side effects and your mood. The exact schedule is set by your prescribing doctor, based on your health, your results and the product information.

Why are liver and blood fat tests needed?

Isotretinoin can raise liver enzymes and blood fats, particularly triglycerides, in some people. If triglycerides cannot be kept at an acceptable level, or if there are symptoms of pancreatitis, treatment is stopped. Very high triglyceride levels (above 9 mmol/L) are sometimes linked with pancreatitis.

When are the blood tests done?

The product information for Roaccutane advises liver tests and fasting lipids:

before starting treatment
one month after starting
then every three months, unless more frequent monitoring is clinically indicated

People with diabetes, obesity, high alcohol intake or a disorder of fat metabolism may need more frequent checks of blood sugar and blood fats. Your prescriber may arrange extra tests if they are clinically needed.

What pregnancy tests are needed?

For anyone who could become pregnant, pregnancy tests must be medically supervised. The product information sets out:

a test before the first prescription, after at least one month of effective contraception
a test each month during treatment, done on the day of the prescription or in the 3 days before it
a final test one month after stopping treatment

The pregnancy test, prescription and dispensing should ideally all happen on the same day, and the prescription must be dispensed within 7 days.

What else is checked at reviews?

Reviews usually cover how your acne is responding, dryness of the skin, lips, eyes and nose, headaches, changes in vision including night vision, muscle or joint pain, any other new symptoms, and your mood. Mood should be checked before, during and after treatment.

Mental health warning: if you notice low mood, depression, anxiety, aggression, unusual changes in mood or behaviour, or any thoughts of self-harm or suicide while taking isotretinoin, contact your prescribing doctor straight away so this can be reviewed. If you feel unsafe or at immediate risk, call 999 or 112 or go to your nearest emergency department. It can help to tell a family member or friend that you are taking isotretinoin so they can tell you if they notice a change.

Which medicines and supplements matter?

Tell your prescriber about every medicine and supplement you take. Isotretinoin must not be taken with tetracycline antibiotics, and vitamin A supplements should be avoided. Exfoliating or peeling acne products should not be used at the same time unless your prescriber advises it.

Frequently asked questions

How often will I need blood tests?

The product information advises tests before treatment, one month after starting, and then every three months. Your prescriber may advise more frequent tests depending on your results and health.

Do I need to fast before my blood test?

Yes, for the lipid (blood fat) test. Your doctor or the practice taking the sample will tell you how long to fast.

Can I drink alcohol while taking isotretinoin?

Talk to your prescriber about this. The product information notes that people with a high alcohol intake may need more frequent checks of blood fats and blood sugar.

Do men need blood tests too?

Yes. Liver and blood fat monitoring and mood checks apply to everyone taking isotretinoin. Pregnancy testing applies to anyone who could become pregnant.

What happens if a result is raised?

Your prescriber will decide what to do, which may include repeating the test, reducing the dose or stopping treatment. Treatment is stopped if raised triglycerides cannot be controlled.

Can I donate blood while taking isotretinoin?

No. You should not donate blood during treatment or for 1 month after stopping.

When should I see a doctor?

Contact your prescribing doctor promptly if you miss a blood test, cannot attend a pregnancy test, or notice new symptoms such as severe headache, blurred vision, severe stomach pain, yellowing of the skin or eyes, or dark urine. If you have not started treatment yet and your acne is severe or scarring, you can read about when to talk to a doctor about your acne.

Sources

Reviewed by Dr Tara Treacy, GP with a special interest in dermatology (IMC 411337). Last reviewed: 2 November 2026. General information only; it does not replace an individual medical assessment.