Creams, ointments and gels look harmless, but the strength of a steroid, the amount you apply and where you put it decide whether a treatment works or causes problems. This guide explains steroid potency, how much to use (fingertip units), retinoids and hydroquinone for acne and pigment, 5-fluorouracil for sun damage, and antibiotic ointments and dressings for wounds.
The short answer
- Steroid creams come in four strengths, from mild (hydrocortisone 1%) to very potent (clobetasol 0.05%). Use the weakest one that works, for the shortest time, and be most careful on the face, groin and in children.
- Dose it by fingertip units: one line of cream from the tip to the first crease of an adult finger (about 0.5 g) covers an area the size of two adult palms.
- Retinoids (tretinoin, adapalene) and hydroquinone irritate at first and need daily sunscreen. Avoid retinoids in pregnancy.
How strong is your steroid cream?
Topical corticosteroids calm inflammation in eczema, dermatitis, psoriasis, insect bites and many rashes. Their strength depends on the steroid molecule, not only on the percentage: 1% hydrocortisone is mild, while 0.05% clobetasol is about 600 times more potent. The UK and Australia use four groups; the US uses seven classes, with class 1 the strongest.
| Potency | Examples (brands) | Typical use |
|---|---|---|
| Mild | Hydrocortisone 0.5–1% (Cortaid, Sigmacort, Dermaid) | Face, babies, mild eczema, bites |
| Moderate | Clobetasone butyrate 0.05% (Eumovate), triamcinolone acetonide 0.02–0.1% (Aristocort) | Body eczema, short courses on thicker skin |
| Potent | Betamethasone valerate 0.1% (Betnovate), mometasone 0.1% (Elocon), methylprednisolone aceponate 0.1% (Advantan), triamcinolone 0.5% | Flares of eczema and psoriasis on the body |
| Very potent | Clobetasol propionate 0.05% (Dermovate, Clobex) | Thick psoriasis, hands, feet, lichen sclerosus; specialist-guided |
Ointments are greasier but usually more effective and less irritating on dry skin; creams suit weeping or hairy areas; lotions and foams suit the scalp. Tube sizes and strengths for one of the most common prescriptions are in triamcinolone cream strengths and tube sizes.
How much cream should you use?
Too little cream is a more common problem than too much: under-treated eczema flares again, and people end up using steroids for longer. The fingertip unit (FTU) makes dosing practical.
| Area (adult) | Fingertip units per application |
|---|---|
| Face and neck | 2.5 |
| One hand (both sides) | 1 |
| One arm | 3 |
| One foot | 2 |
| One leg | 6 |
| Front of trunk | 7 |
| Back and buttocks | 7 |
Apply once or twice daily as directed, usually for a few days to two weeks, then step down to a weaker cream or twice-weekly “maintenance” use if your doctor recommends it. Apply moisturisers (emollients) separately, ideally 15–30 minutes apart.
Don’t use steroid creams on untreated fungal infections (they can spread and change appearance, called “tinea incognito”), on acne or rosacea, on broken or infected skin unless prescribed, or for long periods on the face, eyelids or groin. Long-term use of potent steroids can thin the skin, cause stretch marks and, rarely, withdrawal flares. If you accidentally get cream in your mouth, see brushed your teeth with hydrocortisone?
Steroid injections into the skin
Dermatologists inject a diluted steroid, usually triamcinolone acetonide (Kenalog), directly into painful acne cysts, keloid and hypertrophic scars, alopecia areata patches and some forms of eczema. Strengths are much lower for the face than for scars. The main risks are a temporary dent (atrophy) and lightened skin. This is a clinic procedure; read how Kenalog is diluted for acne cyst injections.
Retinoids and hydroquinone: acne, ageing and pigment
Topical retinoids (tretinoin, adapalene, tazarotene, trifarotene) speed up skin cell turnover, unblock pores and, with long-term use, soften fine lines and even out pigment. Adapalene 0.1% (Differin) is sold over the counter in the US; tretinoin needs a prescription in most countries. Start two or three nights a week with a pea-sized amount for the whole face and build up as tolerated. Expect dryness and peeling for the first 4–6 weeks.
Hydroquinone lightens dark patches (melasma, post-inflammatory pigmentation) by blocking pigment production. It is prescription-only in the UK, EU and Australia, and since 2020 it is no longer legally sold over the counter in the US. Dermatologists often combine it with tretinoin, or use a triple cream with a mild steroid, for 8–12 weeks followed by a break. See how to use hydroquinone and tretinoin together.
Pregnancy: don’t use topical retinoids if you are pregnant or trying to conceive. Oral isotretinoin (Roaccutane, Accutane) causes serious birth defects and requires a pregnancy prevention programme.
Treating sun damage: 5-fluorouracil and calcipotriol
Actinic (solar) keratoses are rough, scaly patches caused by sun damage that can occasionally turn into skin cancer. Fluorouracil cream (Efudix, Efudex) destroys the abnormal cells: the skin becomes red, crusty and sore before it heals. A newer approach combines 5-fluorouracil with calcipotriol (the vitamin D cream used for psoriasis) for only 4 days, which triggers an immune response with a shorter reaction. See fluorouracil and calcipotriene together.
Cuts, grazes and wound care
Most small wounds heal best when cleaned with running water, kept moist and covered. The options:
| Product | Examples | When to use |
|---|---|---|
| Petroleum jelly | Vaseline | Clean minor wounds; keeps them moist, no allergy risk |
| Antiseptic | Povidone-iodine (Betadine), chlorhexidine | Dirty grazes, before covering |
| Antibiotic ointment | Neosporin (neomycin, polymyxin B, bacitracin), mupirocin (Bactroban), fusidic acid (Fucidin) | Localised infection; not needed for clean wounds; neomycin is a common allergen |
| Hydrocolloid dressing | Compeed, DuoDERM, “blister plasters” | Clean, shallow wounds and blisters; seals and keeps moist for several days |
| Non-stick dressing | Melolin, Telfa | Grazes that ooze; change daily |
Ointments and hydrocolloids don’t mix well; see Neosporin under a hydrocolloid bandage.
Vaginal and vulvar treatments
Some skin medicines are made for intimate use: metronidazole gel (MetroGel-Vaginal) and clindamycin cream for bacterial vaginosis, clotrimazole and miconazole for thrush, oestrogen creams for menopausal dryness, and occasionally low-dose testosterone cream prescribed for specific vulvar conditions. Discharge changes during and after these treatments are common and usually harmless; see discharge after metronidazole gel and how testosterone cream is applied to the vulva.
When a skin problem needs a doctor
See a doctor for a rash that spreads quickly or comes with fever, a wound that becomes hot, swollen, increasingly painful or has red streaks, a mole or spot that changes shape, colour or size, bleeds or won’t heal, eczema that hasn’t improved after 2 weeks of correct treatment, or any skin reaction around the eyes, mouth or genitals with blistering.
Articles in this guide
Each article answers one specific question in depth.
- Kenalog (Triamcinolone) Injections for Acne Cysts: How They're DilutedCortisone shots for cysts use triamcinolone diluted to about 2.5–5 mg/mL. What clinicians do, results, side effects like dents, and why not DIY.
- Triamcinolone Cream Strengths and Tube SizesTriamcinolone acetonide comes in 0.025%, 0.1% and 0.5% strengths and tubes from 15 g. How much to use (fingertip units) and how long a tube lasts.
- Fluorouracil and Calcipotriene Together: What to ExpectThe 4-day 5-FU plus calcipotriene regimen for actinic keratoses: how to apply it, the expected redness, aftercare and when to call your dermatologist.
- Accidentally Brushed Your Teeth with Hydrocortisone Cream?A small amount of hydrocortisone cream in the mouth is rarely harmful. What to do now, when to call poison control, and how to avoid tube mix-ups.
- Can You Use Neosporin Under a Hydrocolloid Bandage?Ointment under a hydrocolloid dressing stops it sticking and sealing. When to use which, and how to care for a wound with each.
- How to Use Hydroquinone and Tretinoin TogetherHydroquinone and tretinoin are a classic melasma pair. Application order, triple cream, irritation control, sun protection and treatment breaks.
- How Is Testosterone Cream Applied to the Vulva?Low-dose testosterone cream is sometimes prescribed for vulvar symptoms. How it's usually applied, typical amounts, side effects and monitoring.
- Discharge After Metronidazole Gel: What's Normal?Gel residue, old blood or a yeast infection can all cause discharge after vaginal metronidazole. How to tell them apart and when to see a doctor.
Frequently asked questions about skin treatments
Can I buy mupirocin without a prescription?
In the UK, Australia and the US, mupirocin (Bactroban) is prescription-only to limit antibiotic resistance. Over-the-counter options for minor wounds include antiseptics and, in the US, Neosporin or bacitracin.
What is clobetasol with neomycin and clotrimazole used for?
Triple combination creams (a very potent steroid, an antibiotic and an antifungal) are sold in some countries for mixed infected rashes. Using a very potent steroid on unclear rashes can make fungal infections worse and thin the skin, so these should only be used for a short course on medical advice.
How long does Betadine take to dry?
Povidone-iodine needs to stay on the skin for about 2 minutes, and until dry, to reach its full antiseptic effect. Let it air-dry before covering the area.
Is it safe to use hydroquinone with isotretinoin?
Isotretinoin makes skin very dry and sensitive, so most dermatologists pause hydroquinone and other irritating products during a course and treat pigment afterwards. Ask the prescribing dermatologist before combining them.
Sources and further reading
Taking medicinesCan you cut it in half? What if you miss or double a dose? Are expired tablets safe? Practical rules for…
Combining medicinesWhich medicines clash and why: duplicate ingredients, NSAID combinations, sedatives, alcohol and blood pressure…
Pain reliefHow paracetamol (Panadol), ibuprofen (Nurofen), aspirin and diclofenac differ, safe doses, combining them, and who…