Ketrel 0.05% - Tretinoin Cream

In short: Ketrel 0.05% is a prescription tretinoin cream made by Laboratoires Bailleul, containing 0.5 mg of tretinoin (all-trans retinoic acid) per gram in a 30g tube. It is indicated for acne, including comedonal and mixed acne (not acne rosacea). Prescription-only medicine. Medical assessment required.

What is Ketrel 0.05% cream?

Ketrel is a branded tretinoin cream from the French manufacturer Laboratoires Bailleul. "Ketrel" is the brand name; the active ingredient is tretinoin, a vitamin A-derived retinoid and a prescription-only medicine in the UK.

Brand / manufacturer	Ketrel / Laboratoires Bailleul
Active ingredient	Tretinoin (all-trans retinoic acid)
Strength	0.05% w/w (0.5 mg per gram)
Format	Topical cream
Tube size	30g
Route	Topical
Labelled indication	Acne (vulgaris, mixed/polymorphic, microcomedonal); not acne rosacea
Legal status (UK)	Prescription-only medicine

What is Ketrel 0.05% cream used for?

The Ketrel leaflet lists acne vulgaris, mixed (polymorphic) acne and acne where microcomedones are prominent. It is not indicated for rosacea. Use for photoageing, rough texture or uneven pigmentation is off-label and decided at the medical assessment.

How does tretinoin work?

Tretinoin is all-trans retinoic acid, the biologically active form of vitamin A. It binds directly to retinoic acid receptors (RAR) in skin cells, so, unlike retinol or retinal, it does not need to be converted by the skin first. In acne it normalises the way cells inside the hair follicle are shed, reducing the sticky plugs (microcomedones) from which blackheads, whiteheads and inflamed spots develop, and helps clear existing comedones. Increased cell turnover is also why tretinoin is studied for photoageing, fine lines and uneven pigmentation, although these are off-label uses decided individually.

What does the strength mean?

0.05% means 0.5 mg of tretinoin per gram: a mid strength between 0.025% and 0.1%. Ketrel is one brand at this strength; different brands use different cream bases.

Strength	Tretinoin per gram	Relative concentration
0.025%	0.25 mg	Lowest common strength
0.05%	0.5 mg	Twice 0.025%; available as cream or gel
0.1%	1 mg	Highest common strength; four times 0.025%

A higher percentage is a higher concentration, not automatically a better choice. The strength and format are decided by the prescriber after a medical assessment.

Cream or gel?

Ketrel uses a carbomer-based cream with liquid paraffin and glycerol. Its 30g tube is larger than the common 20g size.

How is Ketrel 0.05% cream applied?

Use Ketrel 0.05% cream exactly as directed by the prescriber. General product information describes:

• Applying once a day, usually in the evening, to clean, completely dry skin (many people wait 20–30 minutes after washing to reduce stinging).
• Using a pea-sized amount for the whole face, spread thinly over the affected area rather than only on individual spots.
• Avoiding the eyes, nostrils, mouth corners, broken, sunburnt or eczematous skin.
• Starting gradually (for example every second or third night) if advised, to help the skin adjust.
• Washing hands after application. More product does not work faster and increases irritation.

What to expect: a typical timeline

• Weeks 1–4: dryness, flaking, mild redness or stinging are common as the skin adapts (sometimes called "retinisation"). Some people notice a temporary flare of spots, often called the tretinoin purge.
• Weeks 6–8: clearer pores and fewer new breakouts usually start to show.
• Weeks 12 and beyond: fuller acne results are generally assessed at around three months. Changes in texture and fine lines take longer, typically six months or more of consistent use.

Timescales vary between individuals and are not guaranteed outcomes.

Side effects

The most common effects are local: dryness, peeling, redness, a warm or stinging feeling, and increased sensitivity to sun, wind and cold. Temporary lightening or darkening of the skin has been reported. Stop applying and seek advice from the prescriber if there is severe redness, swelling, blistering or crusting.

Who should not use tretinoin?

• Anyone who is pregnant, trying to conceive or breastfeeding (topical retinoids should not be used in pregnancy).
• People with eczema, sunburn or broken skin on the treatment area.
• People with a personal or family history of skin cancer (cutaneous epithelioma).
• Anyone using photosensitising medicines (for example some tetracyclines, fluoroquinolones, thiazides) unless reviewed by the prescriber.

All medicines, skin conditions and allergies should be disclosed at the medical assessment.

Sunscreen and skincare alongside tretinoin

Tretinoin makes skin more sensitive to UV, so a broad-spectrum SPF 30–50 every morning is essential, along with avoiding sunbeds. A gentle cleanser and a fragrance-free moisturiser help with dryness. Avoid using other exfoliating acids (AHA, BHA), scrubs, benzoyl peroxide or retinol at the same time unless the prescriber advises it.

Ingredients

Active: tretinoin 0.5 mg/g. Excipients include isopropyl myristate, carbomer, polysorbate 80, glycerol, liquid paraffin, butylated hydroxytoluene, butylated hydroxyanisole, methyl and propyl parahydroxybenzoate (parabens), sodium hydroxide, purified water.

Storage

Store below 25°C in the original carton to protect from light; keep the tube closed and do not use after the expiry date.

Frequently asked questions

Can I get Ketrel 0.05% cream in the UK?

Yes, on prescription only. Tretinoin is a prescription-only medicine (POM) in the UK and cannot be bought over the counter. A medical assessment is required, and answers are reviewed by UK registered doctors who decide whether it is suitable.

Is Ketrel the same as tretinoin?

Yes. Ketrel is a brand name; its active ingredient is tretinoin 0.05%.

Can Ketrel treat rosacea?

No. Acne rosacea is excluded from Ketrel's indications, and tretinoin can aggravate rosacea.

Can Ketrel be used every night?

Many people build up to nightly use over a few weeks. Frequency is set by the prescriber and adjusted to how the skin tolerates it.

Is tretinoin the same as retinol?

No. Retinol is a cosmetic ingredient the skin must convert (retinol → retinal → retinoic acid) before it acts. Ketrel 0.05% cream contains tretinoin, which is retinoic acid itself, so it is more potent, more likely to irritate, and prescription-only.

Is topical tretinoin the same as isotretinoin?

No. Isotretinoin (sometimes known by the former brand Roaccutane) is an oral acne medicine with very different risks and monitoring. Topical tretinoin is applied to the skin.

What is the tretinoin purge?

Some people get a temporary increase in spots in the first 2–4 weeks as tretinoin brings existing microcomedones to the surface. It usually settles within 6–8 weeks. Spots in new areas, or that persist beyond 8–12 weeks, should be discussed with the prescriber.

Can tretinoin be used during pregnancy?

No. Tretinoin should not be used during pregnancy, when planning a pregnancy or while breastfeeding without specific clinical advice. Stop using it and contact the prescriber if you become pregnant.

Does skin need to peel for tretinoin to work?

No. Peeling is a common side effect while the skin adjusts, not a sign of effectiveness. Persistent or severe peeling should be reported to the prescriber.

Further information

Read our tretinoin guide for how tretinoin strengths and formulations compare, or start a prescription skincare consultation.

Sources: BNF: Tretinoin · NICE CKS: Acne vulgaris · manufacturer prescribing information. General information, not medical advice. Written by Skin by Science.