Medication

Tretinoin

A prescription vitamin A cream or gel for acne. It works underneath the skin, on the plug that forms weeks before a pimple appears.
Dr. Schwarz, MD · Board-certified dermatologistLast reviewed August 23, 2026
A plain white medicine tube lying at an angle on a white background, capped, labeled Tretinoin in black with a navy blue swoosh curving along its length.

Start here

Dermatologists love tretinoin, and decades of research back it up. It works on acne, sunspots, and collagen — expect results for pigment and acne in about 3 months. The collagen benefit is real but slow, building over years. Most skincare is overhyped; tretinoin is hyped about right.

— Dr. Schwarz, Board Certified Dermatologist

Key Facts

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Also calledRetin-A, Retin-A Micro, Altreno, Atralin, Avita
Drug classTopical retinoid, a vitamin A derivative
Applied asCream, gel, microsphere gel or lotion
Typical courseLong term, often years
Time to work8 to 12 weeks
Prescription onlyYes

What It Is

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Tretinoin is a prescription form of vitamin A you put on the skin. It is a retinoid — a vitamin A relative that acts on receptors inside skin cells. Approved for acne in 1971, it is still one of the world's most used acne treatments. It also treats fine lines and uneven tone — the changes that unclog pores also thicken skin over time.

How It Works

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Tretinoin has no single mechanism. It acts in three different places in the skin, and which one matters depends on why you were given it. The figures below take them one at a time.

All three start the same way. Tretinoin binds a receptor inside the cell and changes which genes that cell reads. It is not an exfoliant. The peeling in the first weeks is a side effect of that change, not the reason it works — which is why scrubbing does nothing similar.

Acne treatments do not all do the same thing. Here is where Tretinoin acts, and what the others do instead.

Pick a treatment
Skin basics
POREEPIDERMISMELANOCYTESDERMISOILGLANDBACTERIACOLLAGENKILLS BACTERIAUNCLOGS THE PORESPEEDS UP CELL TURNOVERSTOPS PIGMENT MOVING UPUNCLOGS THE POREBUILDS COLLAGENFADES DARK SPOTSUNCLOGS THE POREKILLS BACTERIALOWERS OILFADES DARK SPOTSKILLS BACTERIALOWERS OIL PRODUCTIONSHRINKS THE OIL GLANDUNCLOGS THE POREEPIDERMISMELANOCYTESTHE POREOIL GLANDBACTERIACOLLAGENTHE DERMIS

Benzoyl peroxide releases oxygen inside the pore, and the bacteria involved in inflamed acne cannot live in it. It is the fastest of these on red, sore spots, and the one thing that stops acne bacteria becoming resistant to antibiotics.

Salicylic acid dissolves in oil, so it gets down inside the pore rather than sitting on the surface, and loosens the plug of dead skin and sebum blocking the way out. That suits blackheads and whiteheads more than deep, sore spots.

Retinoids change how the pore lining sheds, so plugs stop forming in the first place — which is why they prevent spots rather than treat the ones already there. Given months they also slow pigment reaching the surface and push fibroblasts to build collagen.

Azelaic acid does three things at once: loosens the plug in the pore, reduces the bacteria in it, and calms the pigment cells that leave a dark mark behind. That combination makes it useful on deeper skin tones, where the mark often outlasts the spot.

Niacinamide turns oil production down a little and interrupts pigment being handed to the cells above. The evidence for clearing spots is thin; it earns its place for the marks left behind, and for making stronger actives easier to tolerate.

Clindamycin is an antibiotic that quiets the bacteria in an inflamed pore. Used on its own it stops working within months as they adapt, so it is always paired with benzoyl peroxide or a retinoid.

Spironolactone blocks the hormone signal telling oil glands how much to make. It works on the pattern rather than the individual spot, over three to six months, which is why it suits deep jawline acne that flares with the cycle.

Isotretinoin shrinks the oil glands themselves, and much less oil means less of everything downstream: fewer plugs, fewer bacteria, less inflammation. It is the only acne treatment that often keeps working after the course ends.

The outer layer, and the only one anything in a jar reaches. It renews itself constantly: a cell made at the bottom takes about a month to reach the surface and flake off. Most of what a skincare product does, it does here.

The cells that make pigment. They sit along the base of the epidermis and hand melanin to the cells around them, which is what gives skin its colour. Dark marks, melasma and the patch left behind by a spot are all these cells making more than usual.

A narrow tube running from the surface down into the skin, with an oil gland at the bottom of it. Oil travels up and out. When the tube blocks, what is behind it has nowhere to go — which is where blackheads and spots start.

Makes sebum, the oil that keeps the surface soft and stops water escaping. How much it makes is set by hormones, not by how often you wash — which is why scrubbing does not fix oily skin.

Cutibacterium acnes lives in the pores of everyone with skin. It is not an infection and it is not a hygiene problem. It only causes trouble when a pore blocks and it multiplies in the oil trapped behind it.

The scaffolding in the dermis that keeps skin firm and springy. It is built by fibroblasts and broken down by age, sun and smoking. Lines and looseness are collagen lost faster than it is replaced.

The living layer underneath, holding the blood vessels, the nerves and the collagen. It is where lasting change happens and it is hard to reach: most of what is sold for the skin never gets this far.

What It Treats

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Close-up of a cheek with inflamed acne. Raised pink-red bumps, a few with yellow-white heads, sit in a patch of redness, and the skin between them is dry and flaking.
Acne
Strong evidence
The most studied topical in acne. Stronger than adapalene and more irritating with it, so it is usually the step up rather than the starting point. Not used in pregnancy.
Wrinkles and Fine Lines
Wrinkles and Fine Lines
Strong evidence
The best-evidenced cream for wrinkles, with repeated trials showing improvement in fine lines, texture and pigment over three to six months. It works by signalling the skin to build its own collagen, so it thickens the dermis rather than thinning it. The usual failure is going nightly from day one, peeling for two weeks and stopping — two or three nights a week with moisturizer underneath gets far more people to six months. Generally avoided in pregnancy — ask your doctor.
Close-up of the lower cheek, nose and mouth of a young person with medium-brown skin, turned three-quarters away from the camera against a pale blue background. Scattered flat dark brown marks are spread across the cheek, with a few small raised spots still active among them.
Post-Inflammatory Hyperpigmentation
Strong evidence
Sheds pigmented surface cells faster and treats the acne writing new marks, which is why it does two jobs on this page. It is stronger than an over-the-counter retinol and correspondingly more irritating at first. Build up slowly, because the peeling, stinging phase is inflammation and can darken the marks before it lightens them.
Close-up of the lower cheek, mouth and jaw of a young person with light skin, turned three-quarters away from the camera against a pale blue background. Scattered flat pink-red marks cover the cheek and run down towards the jaw. The skin surface is smooth and even, with no raised spots and no change in texture.
Post-Inflammatory Redness
Moderate evidence
Prescription strength retinoid, used here mainly to stop new inflamed spots, with the useful side effect of evening out overall tone as the skin turns over faster. It does not target the vessels directly. The first six to eight weeks are red and flaky, so it is worth knowing that the marks will look worse before they look better.
Close-up of the cheek, nose and mouth of an adult with light skin, turned three-quarters away from the camera against a pale blue background. The surface of the cheek is uneven, dimpled with shallow depressions and small pits that catch the light. There are no active spots — the change here is in the texture of the skin rather than its color.
Acne Scarring
Moderate evidence
The prescription retinoid, stronger than retinol, used nightly over months. It improves surface texture and the marks around scars, and it keeps the acne that makes new scars under control. It does not fill an indented scar, and it is usually paused before resurfacing procedures.
Keratosis Pilaris
Keratosis Pilaris
Moderate evidence
The prescription version of the retinoid idea: it normalizes how the follicle sheds, so plugs form more slowly. It is used when over-the-counter acids have not been enough after six weeks. It is drying and irritating on arms and thighs, so it is introduced two or three nights a week, and it makes the skin more sun-sensitive.
Ingrown Hairs
Moderate evidence
The prescription-strength version of the retinoid approach, used at night on the beard and neck. It keeps follicle openings clear and does more for the dark marks than anything else on a shelf. It makes skin drier and more easily irritated by a razor for the first month or two, so build up slowly and shave more gently while you do.
Stretch Marks
Stretch Marks
Moderate evidence
The one cream with real evidence behind it, and only on marks that are still red or purple. Used nightly over months it can make new marks narrower and less obvious by prompting collagen while the skin is still remodeling. It irritates, so it is built up slowly. It must not be used in pregnancy or while breastfeeding, which rules out the most common cause of stretch marks.
Dark Circles Under the Eyes
Dark Circles Under the Eyes
Moderate evidence
A prescription retinoid that thickens the lid skin and speeds pigment out of it, and it makes hydroquinone work better, which is why the two are usually prescribed together. Eyelid skin irritates readily, so it is used at low strength, a few nights a week, and irritation is a reason to slow down rather than push on. Ask your doctor before using it if you are pregnant or trying to be.
Sun Spots (Solar Lentigines)
Sun Spots (Solar Lentigines)
Moderate evidence
The prescription retinoid, and the one with real trial evidence in sun spots specifically. It lightens spots over about six to ten months and improves the sun-damaged skin around them at the same time. Expect dryness and flaking early on, and use it at night with daily sunscreen, since it leaves skin more sun-sensitive. Ask your doctor about it if you are pregnant or trying to become pregnant.
Melasma
Melasma
Moderate evidence
Speeds up how quickly pigmented skin cells are shed, and helps the other creams get in, which is why it is more often part of a combination than used alone. Used by itself it works slowly and it can irritate, and irritation darkens melasma, so it is started at a low strength a few nights a week. Ask your doctor about it if you are pregnant or trying to become pregnant.

Not the Best For

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Milia
Limited evidence
The prescription-strength version of the same idea as adapalene, used at night when there are many milia or they keep coming back. Over two to three months it reduces how many new ones form. It does not clear the existing bumps, and it is used carefully near the eyes. Ask your doctor about it if you are pregnant or trying to become pregnant.
Warts
Warts
Limited evidence
A retinoid cream used for the flat warts that appear in groups of dozens on the face and the backs of the hands, where acid and freezing would be too harsh over so wide an area. It speeds up the turnover of the infected surface cells. It takes months, and it makes the skin dry and sun-sensitive while it runs.
Molluscum Contagiosum
Molluscum Contagiosum
Limited evidence
A retinoid dabbed onto individual bumps to irritate them into clearing. It is sometimes chosen for bumps on the face, where blistering or scraping is less appealing. The evidence for it in molluscum is thin, it is slow, and it makes the skin around the bumps red and flaky, which is its own reason to scratch.
Actinic Keratosis
Actinic Keratosis
Weak evidence
A prescription retinoid people often ask about here, because it is known for sun-damaged skin. It smooths texture and helps the mottled color, but trials have not shown that it clears actinic keratoses or prevents skin cancer. It is reasonable for the look of sun damage, and it is not a treatment for the patches themselves.
Close-up of pink raised bumps, some with small white tips, on flaking skin
The pimple you have today
Doesn't work
Tretinoin works on the plug that forms weeks before a spot appears. It does almost nothing to a pimple already sitting on your face, which is why the first month feels like nothing is happening.
Close-up of the cheek, nose and mouth of an adult with light skin, turned three-quarters away from the camera against a pale blue background. The surface of the cheek is uneven, dimpled with shallow depressions and small pits that catch the light. There are no active spots — the change here is in the texture of the skin rather than its color.
Acne scars
Doesn't work
It smooths rough texture and fades the dark marks acne leaves. Indented scars are missing tissue underneath, and nothing in a tube fills them back in.
Close-up of a cheek with pink flushing and fine visible red blood vessels beside the nose
Redness and flushing
Makes it worse
Rosacea is inflammation in the blood vessels, not a blocked pore. Tretinoin usually irritates it rather than settling it.
Deep lines and folds
Doesn't work
Tretinoin softens fine lines over months of nightly use. Deep creases and folds change very little, because the cause of those sits below what a cream reaches.

Forms

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Gels are drying, which suits oily skin; creams and lotions are gentler. Microsphere and micronized versions release the drug slowly — less irritation, and they survive daylight better.

A white cream tube lying on its side on a white background, with a plain white label reading Tretinoin Cream and a blue swoosh beneath it.
The gentlest vehicle
Cream
The usual starting point for dry or sensitive skin.
A white cream tube lying on its side on a white background, with a plain white label reading Tretinoin Gel and a blue swoosh beneath it.
Oily skin
Gel
Drying, and better suited to oily skin. Plain gels are also the most fragile in daylight, which is one reason tretinoin is a night medicine.
Slow release
Microsphere gel
The drug is held in tiny spheres and let out gradually. Less irritating at the same strength, and far more stable in light — after eight hours of UVA a micronized gel lost 9% of its tretinoin where a conventional gel lost 72%.
A white cream tube lying on its side on a white background, with a plain white label reading Tretinoin Lotion and a blue swoosh beneath it.
Large areas
Lotion
The newest vehicle, designed to spread easily over the chest and back. Brand only, so usually the most expensive option.
Benzoyl peroxide + clindamycin
Combination creams
Both ingredients are microencapsulated separately so they do not degrade each other in the tube. This is the co-formulation the old "never mix them" rule says is impossible.

Strengths

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Start low and move up only if your skin tolerates it. Not every strength comes in every vehicle, so your tube may not offer the next step up. A microsphere gel is gentler than a plain gel at the same number.

WeakestStrongest
0.01% to 0.025%0.05%0.1%
Where most people start
0.01% to 0.025%
The gentlest end, and enough for most people. Stay a few months.
The middle
0.05%
The most prescribed strength, and the usual step up if the lower one was comfortable but not enough.
The strongest
0.1%
Clears slightly faster in trials, and irritates more. Worth it only if you have tolerated 0.05% for months.

Basics

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When to Apply
At night only, on clean dry skin. Wash, dry fully, then spread a pea-sized amount over the whole face — not just the spots. Moisturizer before or after, either way.
How to Start
Every other night for two to four weeks. Go nightly once you have had two weeks with no stinging or flaking.
If It Irritates
Drop to every second or third night, or put moisturizer on first and the tretinoin on top. Either works.
If It’s Not Working
Give it twelve weeks before judging. If acne has stalled, ask your doctor about a higher strength or a second treatment.

Sample Routine

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Here is where Tretinoin sits in a day, and what goes around it. Pick what you are treating and what your skin is like, and the rest of the routine changes to suit.

What to Expect

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First few minutes | Applying it
A pea-sized amount on dry skin at night. Stinging is common early.
Weeks 1 to 3 | Adjusting
Dryness, flaking and stinging peak around week three. This is retinization, and the acne looks much the same.
Weeks 3 to 12 | Settling
Irritation settles and the first real results show.
Weeks 4 to 8 | Sun spots
Sooner than most expect. Dark patches lighten within a month or two and keep fading; in one ten-month trial, 83 percent had lighter spots by the end.
Weeks 8 to 12 | Judge it here for acne
Blackheads and whiteheads go first; red inflamed spots take longer. If nothing has changed after twelve weeks, change the strength or the plan.
Months 3 to 6 | Fine lines
They soften gradually with nightly use.

What to Avoid

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  • Sun Two reasons, and most advice gives only one. Tretinoin makes skin burn more easily, so wear sunscreen daily. Daylight also destroys the drug — UVA breaks it down — so it is a night medicine.
  • Eyes, lips and corners of the nose The skin is thinnest there, and that is where it stings, flakes and stays sore. Stop short rather than blending in.
  • Scrubs, alcohol toners and strong acids While you are adjusting. They add irritation without adding benefit.
  • Waxing and laser hair removal Skin can lift off. Stop about a week beforehand.
  • Broken, raw or sunburnt skin Wait until it has healed.

Monitoring

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No blood tests and no routine labs. Monitoring is a visit at about twelve weeks — is it working, should the strength change?

People stay on this for years, and nothing builds up. Skin usually becomes less irritated over time, not more, so a strength that was impossible at the start may be comfortable a year in. Once you are stable, a yearly review is enough.

If You Stop

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No rebound, no withdrawal, no taper. Pores return to clogging at their old rate and acne comes back over two to three months. Many people drop to a few nights a week rather than stopping.

Cost

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Generic tretinoin cream and gel are widely available and usually the cheapest prescription retinoid. What costs money is the newer vehicles — branded lotions, microsphere gels and combination creams often need prior authorization and can cost many times a plain generic tube. Adapalene is a related retinoid sold without a prescription and a reasonable substitute if cost is the barrier. It is gentler, it is stable alongside benzoyl peroxide by design, and the guidelines grade the two in the same band.

Ask Your Doctor

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If you take other sun-sensitive medicines
Water pills, antibiotics and sulfa drugs do this too. Ask whether anything you take is one of them.
If you have eczema or sensitive skin
Ask when it is sensible to start.
If you are pregnant or breastfeeding
Or planning one. Ask before starting or continuing.
If you are allergic to tretinoin
Or to an ingredient in its base.
If irritation is still bad after six weeks
It should be settling by then, not building.
If the skin cracks or blisters
Cracking around the mouth or eyes, or any swelling or hives, needs looking at.

How It Compares

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Five adapalene gel 0.1% tubes and boxes lined up on white, including Differin, Effaclar, PanOxyl and NeutrogenaLabeled cutaway diagram of a single skin pore, headed Adapalene. The epidermis is a brick-textured band across the top and the dermis is pink below it, with a yellow oil gland at the base of the pore and a small cluster of bacteria inside it. Three callout lines point in: decreases dead cells in pore and decreases oil production are drawn in dark navy as main effects, and decreases inflammation is drawn in gray as a lesser one.
Adapalene
Different job
gentler, available over the counter, stable alongside benzoyl peroxide. A good first retinoid.
TazaroteneDiagram: how Tazarotene works in the skin
Tazarotene
Better
stronger, better for stubborn acne and dark marks, more irritating.
Trifarotene
Different job
newer, approved for the chest and back as well as the face, brand only.
Three acne wash tubes on white: Differin Deep Cleanser, CeraVe Acne Foaming Cream Cleanser and PanOxylLabeled cutaway diagram of a single skin pore. The epidermis is drawn as a brick-textured layer across the top and the dermis in pink below it, with a yellow oil gland at the base of the pore. Three callout lines point into the pore: decreases dead cells in pore near the opening, kills bacteria at the cluster of bacteria deep in the shaft, and decreases inflammation in the surrounding dermis.
Benzoyl peroxide
Different job
kills bacteria but does not fix the plug. Works best paired with a retinoid, not instead of one.

Myths

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  • "Never use it with benzoyl peroxide." The rule comes from a lab test, not from patients. In a trial of 247 people, a benzoyl peroxide wash and tretinoin microsphere gel used the same morning worked as well as spacing them apart, and there is now an FDA-approved cream with both. If you have an older plain gel, use the two at different times of day.
  • "It thins your skin." It does the opposite. Skin looks thin and flaky for the first few weeks as the surface turns over faster, but over months tretinoin thickens the living layers underneath and builds collagen. That is why it is prescribed for aging skin.
  • "You must wait 30 minutes to apply." Damp skin straight after washing did not cause more irritation when it was tested, and waiting does not help. Apply it when it suits you.
  • "You have to purge before it works." Trial data do not show the breakout you may have been promised in weeks two to six. Dryness and flaking are real; spots genuinely getting worse at week six is worth a conversation, not something to push through. Judge it at twelve weeks.
  • "You cannot use it in summer." You can. It means daily sunscreen, which is advised anyway. Stopping every summer just restarts the adjustment period each autumn.
  • "You have to give up alcohol or certain foods." Nothing you eat or drink affects it — almost none of it reaches the bloodstream. The food and alcohol rules belong to isotretinoin, the tablet — a different medicine.

Questions Patients Ask

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Does tretinoin make acne worse before it gets better?

No, and it is the most repeated claim about the drug. A review hunting for trial data on retinoid-induced flares found none — acne improved even in the first couple of weeks. What does happen is irritation — dryness, flaking and redness peaking around week three and settling by week twelve. That can make your face look angrier without new spots. Lesions genuinely worse at week six are information, not a phase to endure.

Can I just use it on the spots?

No. It prevents the next spot rather than treating today's, so it goes on the whole area that breaks out.

Is the peeling how I know it is working?

No. Plenty of people stop peeling by week four and keep clearing. Chasing peeling is how people end up on a strength they cannot stay on.

Will it thin my skin?

The opposite, over time. It briefly thins the dead surface layer, which is why skin feels smoother and burns more easily early on. Underneath it thickens the living layer and increases collagen — measured on biopsy.

Why at night?

Your skin is more sun-sensitive on it, and daylight destroys the drug. After eight hours of UVA a conventional gel lost about 72% of its tretinoin and a micronized one lost about 9%.

Can I use it with benzoyl peroxide?

Usually yes. The warning comes from a lab test, not from patients — tested properly, the two in one routine worked as well as spacing them apart, and there is now an approved single cream containing both. With a plain older gel, use one in the morning and the other at night.

Is it safe in pregnancy?

It is not recommended in pregnancy, and it is not oral isotretinoin — the two get confused constantly. Published data on topical tretinoin do not show more birth defects, and the newest FDA labels say no drug-associated risk has been established. There is real reassurance if you used it before you knew. Stop once you know, and speak to the doctor managing your pregnancy.

References

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