How to use tretinoin: the steps on the label

Tretinoin is applied once a day at bedtime, in a thin layer, to clean and dry skin where acne appears. The FDA-reviewed label for tretinoin cream gives that direction, and MedlinePlus, the patient site of the US National Library of Medicine, agrees: "Use tretinoin daily at bedtime." This guide lists the steps on the label, the points where labels differ, and what to ask before the first night. For what the drug is and what it treats, see the tretinoin guide.

Skinli gives general education and is not a doctor. Tretinoin is a prescription drug in the US, and its patient leaflet says in capital letters that it is "TO BE USED ONLY ACCORDING TO YOUR DOCTOR'S INSTRUCTIONS". Your prescriber picks the strength, the form and the schedule. Where two labels give different directions, this page shows each one with its source, so you can ask which applies to your tube.

The steps on the tretinoin label

The patient leaflet that comes with generic tretinoin cream is published on DailyMed, the National Library of Medicine's database of drug labels. Its steps, in order:

1. Wash gently. "Use a mild, non-medicated soap. Avoid frequent washings and harsh scrubbing." The cleanser for tretinoin guide covers this step.
2. Dry the skin. Pat it dry with a towel, then wait. The leaflet says: "Let the face dry 20 to 30 minutes before applying tretinoin." Newer labels give a different direction, shown in the next section.
3. Measure a small amount. Squeeze half an inch or less of cream onto a fingertip.
4. Spread a thin layer. The label says to apply it "to the skin where acne lesions appear, using enough to cover the entire affected area lightly." The layer covers the whole area that breaks out.
5. Keep it off sensitive areas. "Keep the medication away from the corners of the nose, mouth, eyes and open wounds." The post on tretinoin on a popped pimple explains the warning about open skin.
6. Wash your hands. The Retin-A Micro gel leaflet adds this step.
7. Moisturize the next morning. The leaflet says to apply a moisturizer, or a moisturizer with sunscreen, that will not clog pores (the label word is noncomedogenic) every morning after washing.

How long to wait after washing

The labels disagree on this step. The older labels give a waiting time, and the newer ones say only to pat the skin dry.

Source	What it says after washing
Generic tretinoin cream leaflet	"Let the face dry 20 to 30 minutes before applying tretinoin."
Retin-A cream and gel leaflet	The same 20 to 30 minutes
Renova cream 0.02 percent, for fine wrinkles	"Pat skin dry and wait 20 to 30 minutes before applying"
Retin-A Micro gel	Cleanse with a mild, non-medicated cleanser "then pat the skin dry." No waiting time is given
Atralin gel and Ziana gel	Pat the skin dry. No waiting time is given
American Academy of Dermatology, routine page	Apply a medicine "right after cleansing"

The generic leaflet gives its reason for the wait: "it is important for skin to be completely dry in order to minimize possible irritation." Each label in the table asks for dry skin, which answers the common question about damp skin.

Skinli's own plan, which uses two gels sold without a prescription, also asks for a fully dry face. A tretinoin prescription follows its own label, so ask your prescriber which waiting time applies to your product.

How much tretinoin to use

Product (source: its label on DailyMed)	Amount
Generic tretinoin cream	Half an inch or less, squeezed onto a fingertip
Ziana gel (tretinoin with the antibiotic clindamycin)	A pea-sized amount for the entire face
Renova cream 0.02 percent	A "small pearl-sized" amount, close to 5 mm across

The generic leaflet gives a way to check the amount: "The medication should become invisible almost immediately. If it is still visible, you are using too much." For the gel, the Retin-A leaflet adds a second sign of too much, which is dry flakes that form from the gel within a minute or so. The tretinoin cream vs gel guide explains the forms.

A larger amount brings no gain. The label says: "If medication is applied excessively, no more rapid or better results will be obtained and marked redness, peeling, or discomfort may occur." The Ziana label tells patients "not to use more than the recommended pea-sized amount and not to apply more often than once daily".

How often to use tretinoin

The standard direction is once a day. The sources differ on whether to begin at that pace.

Source	What it says
Generic tretinoin cream label	Apply "once a day, before retiring"
Generic tretinoin cream leaflet	"Your physician may advise, especially if your skin is sensitive, that you start your therapy by applying tretinoin every other night."
Retin-A Micro gel label	Once daily in the evening. "Efficacy of RETIN-A MICRO at reduced frequencies of application has not been established."
Altreno lotion label	"Apply a thin layer of ALTRENO to the affected areas once daily."
MedlinePlus	Use the amount your doctor prescribed, and use it only as often as prescribed
NICE acne guideline (England)	To reduce irritation, "start with alternate-day or short-contact application (for example washing off after an hour). If tolerated, progress to using a standard application."
American Academy of Dermatology, retinoid page	"use it every other night to start, slowly building up"

Every night is the schedule on the label. Several sources describe a slower start, and the Retin-A Micro label says that efficacy, meaning how well the drug works, has not been established at fewer applications. Skinli gives no schedule of its own. Your prescriber chooses the starting pace and decides when to change it.

One small study tested short contact, which means the cream is washed off after a set time. In a 2013 study in the Journal of Dermatological Treatment, 74 patients applied 0.05 percent tretinoin cream once daily for 30 minutes. Of those patients, 41 (55.4 percent) improved by 50 percent or more, 13 (17.6 percent) had mild irritation, and 4 (5.4 percent) stopped because of severe irritation. The authors call it a pilot study, meaning a first small test, and it had no comparison group, so it cannot show how 30 minutes compares with leaving the cream on overnight.

A second dose in the same day does not speed the result. The leaflet says: "You cannot make tretinoin work any faster by applying more than one dose each day". If you miss a night, MedlinePlus says: "Do not apply extra cream, lotion, or gel to make up for a missed dose."

Why tretinoin goes on at night

The labels set the time. The generic cream label says "before retiring", the Retin-A Micro label says "once daily in the evening", and MedlinePlus says "at bedtime". The American Academy of Dermatology (AAD) says "dermatologists often recommend applying a topical retinoid in the evening."

Two facts in the sources fit a night schedule:

• Sun. The Retin-A Micro label says the gel "can cause photosensitivity", which means the skin reacts more strongly to sunlight. The generic label recommends sunscreen and protective clothing over treated areas. The sunscreen with tretinoin guide gives the SPF numbers from each label.
• Light. A 2008 laboratory study in the International Journal of Pharmaceutics found that tretinoin breaks down under light made to copy sunlight, and that UVA, one type of ultraviolet light, caused most of the breakdown. In a 2002 laboratory test in Cutis, written by staff of Johnson & Johnson Consumer Products, 24 hours of fluorescent light broke down up to 69 percent of the tretinoin in a 0.025 percent gel.

Ask your prescriber before moving tretinoin to the morning, because the time of day is part of the directions.

Makeup, moisturizer and other acne products

Makeup. The generic label says patients "may use cosmetics, but the area to be treated should be cleansed thoroughly before the medication is applied". The Renova leaflet says: "You may use cosmetics 1 hour after applying", and its label asks for the same hour before washing the face. The Atralin leaflet says: "You may use moisturizers and cosmetics."

Moisturizer. The AAD's routine page gives the order as wash, then medicine, then "Apply moisturizer and/or sunscreen." Its acne treatment page lists the ways dermatologists reduce retinoid irritation: a smaller amount, less frequent use, and moisturizer first. It adds: "Only make these changes with your dermatologist's help." The moisturizer with tretinoin guide compares what each label says.

Other acne products. The generic label says: "Particular caution should be exercised in using preparations containing sulfur, resorcinol, or salicylic acid with tretinoin." It also advises a rest for the skin after such products, "until the effects of such preparations subside", before tretinoin is begun. See salicylic acid with tretinoin and retinoid with benzoyl peroxide for those two pairs.

What to know before the first night

Age. Each label states its own age.

Label	Age statement
Generic tretinoin cream	Safety and effectiveness "below the age of 12 have not been established"
Retin-A Micro gel	For acne in "adults and pediatric patients 12 years of age and older"
Altreno lotion	For acne in "patients 9 years of age and older"
Atralin gel	The leaflet says it is unknown whether the gel is safe and effective "in children under 10 years of age"
Renova cream, for fine wrinkles	Safety and effectiveness "in patients less than 18 years of age have not been established"

Strength. Tretinoin comes in several strengths, and the prescriber picks one for you.

The first weeks. The label says application "may cause a transitory feeling of warmth or slight stinging". Transitory means that it passes. Early breakouts are covered in the tretinoin purging guide, skin reactions in tretinoin side effects, and the wait for results in how long tretinoin takes to work.

Areas to avoid. The label says tretinoin "should be kept away from the eyes, the mouth, angles of the nose, and mucous membranes." Mucous membranes are the moist linings inside the nose and mouth. The Atralin label gives a reason for the skin around the eyes and mouth: "the skin is especially prone to irritation." See tretinoin under the eyes.

Pregnancy. If you are pregnant, planning a pregnancy or breastfeeding, tell your prescriber before the first use. The guide to retinoids during pregnancy and breastfeeding covers what the labels say.

No prescription yet. How to get tretinoin explains the steps.

When to stop and call your prescriber

The label gives the prescriber three options when skin becomes irritated: "use the medication less frequently, discontinue use temporarily, or discontinue use altogether." That choice belongs to the prescriber, so report irritation early.

Stop and call sooner in these cases:

• Severe or lasting irritation. The leaflet says: "If you are experiencing severe or persistent irritation, discontinue the use of tretinoin and consult your physician."
• Sunburn. The leaflet says: "If you do become sunburned, stop your therapy with tretinoin until your skin has recovered."
• Blisters, crusts or swelling. The label says the skin of some sensitive people "may become excessively red, edematous, blistered, or crusted." Edematous means swollen.
• No change after 12 weeks. NICE, the guideline body in England, says to review acne treatment at 12 weeks. If your acne is no better by then, or if you get deep, painful lumps or scars at any point, see a doctor or a dermatologist in person.