Medicines & Supplements A to Z > Isotretinoin


Last updated on 16/07/2021.

Overview   |   Dosage   |    Side Effects   |   Precautions  |   Tips  |   Where To Buy  

GENERIC NAME: Isotretinoin


BRAND NAME(S) IN HONG KONG: Roaccutane 保膚靈, Acnotin, Reducar 來膚康

DRUG CLASS: Anti-acne agents

SUB CLASS: Retinoid


– 5 mg, 10 mg, 20 mg (capsules)

What is Isotretinoin for?

Isotretinoin belongs to a class of medications called retinoids (a type of Vitamin A), which works by stopping the formation of pimples in the skin. It is used to treat severe forms of acne which are resistant to treatments with antibiotics or topical therapy.

How to use it?

Isotretinoin is available as a capsule. It should be taken with food or immediately after a meal. Swallow it whole with a glass of water and do not crush, chew, or break the tablet. The dosage is calculated from your body weight in kilograms (kg).

Initially 0.5 mg/kg daily in single or two divided doses, which may increase to 1 mg/kg daily if necessary. The usual treatment duration is 16-24 weeks. If relapse after the first course, repeat the treatment course after at least 8 weeks.

What are the side effects of Isotretinoin?

Common side effects of Isotretinoin include dry skin, muscle/joint/back pain, and eyesight problems, such as blurred vision, eye pain or redness, dry eyes, discomfort when wearing contact lenses and decreased night vision.

Who should not take Isotretinoin?

– People allergic to Isotretinoin or any component of the formulation
– People with Vitamin A toxicity
– People with hyperlipidaemia (high cholesterol and triglycerides in the blood)
– Patients who are currently taking tetracyclines
– Pregnant or breastfeeding women and those who intend to become pregnant

Pharmacist Tips:

– This medication can cause blurred vision and drowsiness. Avoid driving or operating machinery until you know how you respond to Isotretinoin.
– This medication may make the skin sensitive to light. Use sunscreen, wear protective clothing and avoid tanning beds or prolonged exposure to sunlight.
– Isotretinoin can affect fetal development. While taking Isotretinoin, always use two reliable forms of contraceptives for 1 month before therapy, during therapy and 1 month after therapy.  Regular pregnancy tests are also required.
– Do not donate blood during therapy and for at least 1 month after the last dose.
– Avoid waxing as a method to remove hair as this may cause scarring.
– Do not use Vitamin A supplements and avoid taking foods that are rich in Vitamin A, such as cod liver oil.
– If you experience allergic symptoms like skin rashes, difficulty breathing, swollen mouth/lips/eyes, stop using Isotretinoin and report to your doctor immediately.

Common dosing schedule:
Isotretinoin is taken once or twice a day. Take Isotretinoin at meal time.

This schedule is for reference only, adjustments may be made according to individual needs.

Some common medications Isotretinoin may interact with:
– Anticonvulsants, e.g. Phenobarbital, Phenytoin, Carbamazepine
Vitamin A and any supplements/products containing Vitamin A
– Tetracyclines

Please notify your doctor or pharmacist if you are taking the above medication, dosage adjustments might be needed.

Where to buy Isotretinoin in Hong Kong?

In Hong Kong, Isotretinoin is a prescription only medicine, and requires a prescription from a doctor to be purchased in a pharmacy. It can also be obtained from doctors. To find a pharmacy near you, refer to the list of pharmacies (“Authorized Sellers of Poisons”) from the Hong Kong Department of Health.

For more information about drug names and ingredients, you can visit Hong Kong’s Drug Office at

For detailed information about the use of alprazolam in children, pregnancy and breastfeeding, and for questions about drug interactions, please check with your pharmacist or doctor.

Disclaimer: our goal is to provide you with the most relevant drug information and common dosage for Hong Kong. This information does not constitute medical advice. For specific treatment recommendations and advice, always discuss with your doctor or pharmacist, and follow the instructions included with your specific medicine.