Description
About Tretizen 20 mg Soft Capsule
Tretizen 20 mg is a prescription soft capsule containing 20 mg of isotretinoin, made by Zenlabs Ethica, used for severe acne that is nodular, cystic, scarring or resistant to other treatment. Twice the strength of Tretizen 10 mg, it allows many adults to reach their weight-based dose with fewer capsules.
How does isotretinoin work?
This oral retinoid shrinks oil glands and dramatically reduces sebum, keeps pores clear and calms the inflammation that produces deep, painful spots. Because it changes how the skin behaves rather than just killing bacteria, the improvement often lasts well beyond the end of treatment.
How to take Tretizen 20 mg
Take the capsule with food, swallowed whole, once or twice daily as instructed. Dermatologists usually prescribe 0.5 mg/kg a day at first and may increase towards 1 mg/kg a day, over a course of about 16–24 weeks. Do not stop early because your skin looks better; finishing the planned course lowers the chance of acne returning.
What to expect month by month
- Month 1: dry lips within days; skin becomes less oily, though a flare of spots is possible.
- Months 2–3: fewer new spots and cysts; dryness is steady and manageable with moisturizer.
- Months 4–6: most people are largely clear; red marks fade slowly.
- After finishing: dryness settles within a few weeks, while reduced oiliness often lasts much longer.
Pregnancy prevention
Isotretinoin must never be taken in pregnancy, as it causes severe malformations. People who could become pregnant need to follow the UK Pregnancy Prevention Program or, in the US, iPLEDGE. That means two effective contraceptive methods starting one month before treatment and continuing until one month after, plus pregnancy testing before starting, monthly and after the course.
What are the side effects?
- Common: chapped lips, dry skin and eyes, nosebleeds, sun sensitivity, muscle and joint pain.
- Monitored: blood fats and liver enzymes, checked with blood tests.
- Serious but rare: mood changes and suicidal thoughts, raised pressure around the brain, pancreatitis, severe skin reactions.
Stop treatment and seek help at once for depression or thoughts of self-harm, a severe headache with vision changes, severe abdominal pain, or a rash with blisters or peeling.
Who should not take it?
Not for use in pregnancy, breastfeeding, severe liver disease, very high lipid levels or excess vitamin A, or alongside tetracyclines. Tell your doctor about any soya or peanut allergy. Do not donate blood during and for one month after the course, and avoid waxing, laser and skin resurfacing for six months after finishing.
After the course
Keep using a gentle moisturizer and sunscreen. If acne slowly returns, a dermatologist may suggest a topical retinoid for maintenance, explained in our tretinoin guide, or occasionally a second isotretinoin course.
Pack sizes
Strips of 10 soft capsules, sold in packs of 30, 60 or 90, from $25. Store in a dry place, protected from light.
Frequently asked questions
Can I take two 10 mg capsules instead?
Yes, two Tretizen 10 mg capsules give the same dose.
How does it compare with Tretiva 20 mg?
The active ingredient and strength match Tretiva 20 mg; the manufacturer differs.
Where are other acne treatments?
See the acne range.
General information only, not personal medical advice. Tretizen 20 mg is a prescription medicine that must be supervised by a specialist.