What is tretinoin?

Tretinoin is a medication that belongs to a class of drugs known as retinoids. It is derived from vitamin A and is commonly used topically to treat various skin conditions. Tretinoin is well-known for its effectiveness in treating acne and improving the overall appearance of the skin.

Some common uses of tretinoin:

• Acne Treatment: Tretinoin works by promoting cell turnover and preventing the plugging of hair follicles, which can lead to the formation of acne. It helps to reduce the formation of new acne lesions and can also improve the appearance of existing acne scars over time.
• Skin Texture Improvement: Tretinoin can also be used to improve skin texture and tone. It can stimulate collagen production, which can lead to smoother and firmer skin.
• Wrinkle Reduction: Tretinoin is sometimes prescribed as an anti-aging treatment to reduce the appearance of fine lines and wrinkles. It can help improve the elasticity of the skin and reduce the signs of photoaging.
• Hyperpigmentation: Tretinoin can be used to treat certain types of hyperpigmentation, such as melasma or post-inflammatory hyperpigmentation. It can help to fade dark spots and even out the skin tone.

Tretinoin is available in various formulations, such as creams, gels, and lotions, and it is usually applied topically to the affected areas of the skin. It’s important to note that tretinoin can cause skin irritation, redness, and peeling, especially when first starting the treatment. Therefore, it’s advisable to start with a lower concentration and gradually increase as your skin becomes accustomed to the medication. Additionally, tretinoin can make the skin more sensitive to sunlight, so it’s recommended to use sunscreen and limit sun exposure while using this medication.

Tretinoin is often available by prescription only, so it’s important to consult a healthcare professional before using it to ensure it’s appropriate for your specific skin condition and needs.

Tretinoin vs Adapalene vs Tazarotene vs Retinol vs …

Look here for a chart comparing the different types of retinoids.

• Tretinoin binds to RAR alpha, beta, and gamma receptors
• Tazarotene binds to RAR beta and gamma receptors
• Adapalene binds to RAR beta and gamma receptors, but less effectively than Tazarotene (FYI this is the reason why this ingredient is FDA-approved for acne, but not anti-aging)

Tretinoin vs Adapalene vs Tazarotene vs Retinol

While all of them are derivatives of Vitamin A, Tazarotene is the strongest form of topical vitamin A.  Retinoids are fat-soluble compounds, and as such, they are freely and immediately absorbed into our cells upon application, where their receptors, Retinoic Acid Receptors (RAR) alpha, beta, and gamma, can be found. Tretinoin and adapalene, being a form of retinoic acid, can instantly bind to those receptors, but retinol and retinal can not and they need to be converted to retinoic acid first. Retinol converts to retinal, and retinal converts to retinoic acid. For that reason, retinol is much better tolerated, but its effects are also more limited. Because those receptors work by modifying gene expression, all positive effects of tretinoin and adapalene can not be immediate and take time, which is even longer for retinol due to the extra steps necessary.

What is tretinoin good for?

• Treating acne
• Anti-aging (tretinoin is considered the gold standard for anti-aging treatments).
• photodamage (fine wrinkling around the eyes, crease lines around the mouth and cheeks, yellowish skin, telangiectasia over cheeks, periorbital comedones, wrinkling of skin and the backs of the hands, and solar keratosis.)
• PIH (brown-ish hyperpigmentation).

What is tretinoin NOT as good for?

• minimizing redness (increased vascularity means redness can actually INCREASE for some).
• minimizing irritation (tretinoin is one of the most irritating ingredients).
• PIE. Post-irritation erythema. Erythema is the dilation of the blood vessels. Tretinoin increases vascularity — creates more blood vessels — so it can make erythema worse. If you have pale skin, this looks like redness. If you have darker skin, this can look like a “glow”.  If you’re pale, azelaic acid, niacinamide, and vitamin C are better for dealing with hyperpigmentation.

Does tretinoin thin the skin or thicken it?

One study found that the stratum corneum (outermost layer of skin) “became compact in the first 3 to 6 months whereas it returned to normal (basket weave pattern) in 12–24 months and remained normal until the end of the therapy” (source, arg I had it then lost it, once I find it again I’ll add it here.), which sounds like the thinning of the stratum corneum goes back to normal with continued use. This does NOT mean sun sensitivity goes back to normal.

Is Adapalene good for anti-aging?

Inconclusive! Read more here. 

Where can I get tretinoin?

• Search for a reputable dermatologist in your area.
• In UK, you can order online from Tretinoin Uk
• Americans can order tretinoin online from a wide variety of places.
• In some countries, tretinoin is available over the counter.

Is tretinoin photostable?

• Micro gel vs gel formulation: One study found a degradation of 11% after an 8-hr exposure to flourescent light vs a degradation of 86% after 2 hours exposure to fluorescent light for the gel version [citation coming].
• Notes: no studies have been done that compare the cream and gel formulations. Also, both authors of that study reported conflicts of interest with the company that makes the micro version, so they do have a slight reason for bias towards pushing the microionised form. Take that as you will.

Long-term use

• Tret is safe to use long-term. Here is a picture of reasonable results to expect after 9 months on 51-year-old skin.
• It is possibly not safe to use while breast-feeding or while pregnant. Isotretinoin (accutane) causes birth defects, so with an abundance of caution medical providers recommend avoiding tretinoin too. But there have been no studies either way (and there probably will never be: it’s too risky to study pregnant women).

Use while pregnant or trying to conceive

For more information about using Tretinoin during pregnancy or while breastfeeding see: https://mothertobaby.org/fact-sheets/tretinoin-retin-a-pregnancy/

I’ve recently been prescribed tretinoin. What important information should I be aware of?

• Expect to see irritation within 2-3 weeks, and improvement within 4-6 months of starting tretinoin.
• Hydration is key. Use moisturizer both morning and night.
• Start slow! The effects won’t kick in for the first several weeks.
• START SLOW – 2x a week at first, slowly increasing in frequency based on how your skin feels. A tentative schedule might be 2x/week for 2 weeks, 3x/week for 3 weeks, etc. Don’t stick to a schedule if you’re getting extreme irritation. If moisturizer or cleanser stings very badly, take days off to recuperate and mend your skin.
  • Some derms tell you to start every night. This is almost always a mistake. 
• A basic routine is best. Cleanse 1x a day with a gentle cleanser, moisturize twice a day, and apply sunscreen every morning. See below for more routine tips.
• Start gentle! When you’re first using tret, stop all other actives: no BHA, AHA, or other harsh products like benzoyl peroxide or azelaic acid. Vitamin C works for some and not others (you’re the expert on your skin and will have to decide what works for you).
  • This means no other activities at all. Morning AND night.
  • Stop other actives at least one week before starting tretinoin.
  • If your derm prescribed more, then it’s up to you if you want to follow their advice. You have to find the balance between listening to your skin and following your doctor’s orders. We strongly recommend going slow and being very gentle. (Once you’ve been using tretinoin for 6+ months, you can add these back in as needed).

Routine Suggestions

PM Step 1) – Cleanse

• Wash/Cleanse your face with a gentle cleanser and cool water to remove makeup, sunscreen, etc. Gentle cleansers are key. If your face feels ‘tight’ after using your cleanser it is too harsh, get another one.
• Popular cleansers: Cetaphil, CeraVe Hydrating, Vanicream Gentle Hydrating, CeraVe Foaming (tends to be more drying than the Hydrating one).

PM Step 2) – Apply tret and moisturizers

Short contact therapy (the most gentle method):

• Apply tretinoin to your dry, clean skin.
• After ~5-10 minutes, rinse it off.
• Immediately apply moisturizer.
• Slowly increase the amount of time you leave the tretinoin on your face, going up by ~5 minutes every week until your skin is accustomed to it.

Buffering option 1 (The Sandwich method):

• Moisturizer on damp skin after cleansing in step 1 above. Research even shows that moisturizers even enhance the effects especially a moisturizer containing niacinamide. Light serums are less good because they increase absorption and therefore increase irritation.
• Wait for skin to dry
• Apply tret
• More moisturizer, then occlusive (optional) > Bed

Buffering option 2 (The Moisture Blanket method):

• Wait for skin to dry after step 1 cleanse above.
• Apply tret to completely dry skin.
• Wait for tretinoin to dry (~5 mins)
• Apply moisturizer, then occlusive (optional) > Bed
• NOTE: Tretinoin products are designed with normal “trans-epidermal water loss” taken into account. Adding an occlusive on top disrupts the expected water loss, and could cause increased irritation. Always patch-test any changes!!

No buffering option (The Rogue method):

• Wait until your skin is totally, completely dry after cleansing in step 1 above.
• Apply tret > Bed.

AM Step 3) – Apply Moisturizer and SPF

• Wake up
• Splash your face with cool water, and gently rub with your hands. There is no need to use a cleanser in the morning, and it can dry you out even more. Water is enough for most people! (You are the expert on your skin, though, so do what works for you).
• Apply moisturizer. Research even shows that moisturizers even enhance the effects especially a moisturizer containing niacinamide.
• Wait for the moisturizer to dry.
• Apply sunscreen. You should be using a minimum of SPF 50, with PA ++++. More info about sunscreen is below.

General routine tips

• Wear sunscreen. Sunscreen is an absolute must while using tretinoin. If you cannot commit to daily use, find another ingredient to use. Azelaic acid is excellent.
• Always apply retinoids to dry skin. That means either 1) pat-dry your skin after cleansing and wait a few minutes for it to dry completely, or 2) wait for your moisturizer to dry completely. It has long been known that hydration of the stratum corneum increases its permeability. Hydration increases skin permeability overall, and also increases the absorption of topically-applied molecules. Additionally, manufacturers advise using topical drugs on clean and dry skin, so that’s what you should do. If your skin is wet at all when you apply tretinoin, you will likely see an increase in flaking, peeling, and irritation.
• Apply a pea-sized amount of tretinoin to your entire face. Apply a small dot in the center of the forehead, on the cheeks, nose, and chin. Sweep out to the outer parts of the face to spread it. Do not put it directly under eyes, around the mouth or in the nose folds. It may feel as if it is not enough, but it is. The reason for this is because tretinoin being a fat soluble molecule is immediately absorbed by our cells and bound to its receptors. When all of the receptors become saturated, the excess is stored in the cell, and the amount of unused tret in our skin is exactly what has the strongest link to irritation and side effects. So if you’re using more than it’s necessary every time, the amount of free tretinoin in your skin will quickly skyrocket. The best way to check if you’re using more than you should is to gently apply a thin tissue to your face when you finish spreading your tret. The tissue should fall off. If it sticks, you’ve used too much.
• Only apply tretinoin at night. It degrades in the sunlight, so there is no point in wearing it during the day.
• Apply tretinoin evenly to your entire face. Tret is NOT a spot treatment. Uneven application can mean weird patches of irritation and discoloration, especially on darker skin tones.
• Buffering does not decrease effectiveness. For acne treatment, studies show buffering does not cause problems with tazarotene, a relative of tret. We haven’t seen any studies of buffering with tretinoin. Some people in say buffering doesn’t work as well, especially with the micro-gel forms. Redness and flaking are not desirable side effects, minimizing them will not decrease effectiveness. If you don’t have irritation, it doesn’t mean tretinoin isn’t working. It can take 1-3 weeks to feel the effects.
• Use moisturizer! Keeping skin healthy and happy is key to treating acne. Research shows that using moisturizer actually ENHANCES the effects of retinoids especially a moisturizer containing niacinamide. An occlusive like Vaseline or Aquaphor applied on top of moisturizer at night can minimize Trans-Epidermal Water Loss and keep skin moisturized and healthy without clogging pores. Examples of good moisturizers: Cerave in the Tub moisturizer, Vanicream Lite moisturizer, and Cetaphil.

Required: Sunscreen

Sunscreen is *required* when on any retinoid. Not using sunscreen leaves your skin extremely vulnerable to sun damage and does more long-term damage than short-term good.

Dark-skinned folks also need to wear sunscreen.

**If you cannot commit to using sunscreen daily, do not start tretinoin.** Tretinoin makes you sun sensitive for up to 2 weeks so wear sunscreen for up to 2 weeks after stopping Tret. There is no evidence that sun sensitivity returns to normal with long-term use of tretinoin.

• With tret, you need a minimum of SPF 50, PA++++ (UVA protection). A quick reminder that UVA rays cause tanning, hyperpigmented sunspots, and ultimately fine lines and wrinkles. UVB causes sunburn. Both can cause skin cancer.
• The “SPF” rating only rates UVB protection, not UVA protection. UVA protection is rated by PPD (persistent pigment darkening) or the PA system, which classifies PPD levels in a product.
• You always need to apply enough of your sunscreen! When sunscreens are tested for SPF labels, it is always applied at a density of 2 mg/cm squared. The mentioned quantity is needed for sunscreen to form a uniform film on our skin, which is crucial for optimal protection. In reality that translates to about 0.9-1,4 grams of product you need to use every time, for face only. The usual tool of measurement people use so they don’t bother with numbers are ‘fingers’ of sunscreen. For most people, 2 full length fingers of sunscreen (just like this) are enough for face only, and 3 fingers for face, neck, and ears. This method is not perfect because the amount of product that ends up on your fingers significantly varies from product to product, depending on vehicle, thickness, etc. That’s why it would be wise to measure approximately how much product you need, and measure it for every sunscreen you use, because it will vary. There are number of ways to do that:
  • Use teaspoons to measure. About ¼ to ⅓  of a teaspoon would be the amount needed. This is again flawed because you can only measure approximately.
  • Measure the estimated surface area of your face. It should be around 400-500 cm squared, and you can add 10-20% to that taking into account our face is actually a 3D model. Then multiply that by 2 and you’d have the estimated amount of sunscreen you need to apply to your face in milligrams. Get a small 2ml syringe, and use it to measure exactly how much sunscreen you’d need (if we estimate that 1g = 1ml). Now use the syringe to dispense the sunscreen to your palms, or your fingers, so you can get the feeling of how much you should be using each subsequent time.
  • After measuring out your face, measure out the correct amount on a digital scale that measures in milligrams, if you happen to have one.
    
    We just want to note that this is not required for optimal protection, but it is super helpful for preventing you from under or over-applying your sunscreen.
• It is recommended that you reapply sunscreen at least every two hours, and always after showering, swimming, heavy sweating etc. This is because the uniform film that is needed for the sunscreen to properly work breaks down in that period and it needs to be formed again, regardless of if you were exposed to sunlight in that period or not.
• Windows do not block UVA rays, but the amount of UVA rays that reach you indoors depends on many variables. We would like to note that it is still better to wear sunscreen when you don’t need to than accidentally not wearing it when you do need it, so the best practice is still putting on sunscreen every single day regardless of what you’re planning to do that day.
• Sunscreen does not need to sink in to work: both mineral and chemical sunscreens form a film on the skin which mainly absorbs UV rays and prevents sun from causing damage.
• Sunscreen filters have improved a lot in recent years, but the FDA in the US has not yet approved them. They are totally safe and effective, the FDA is just slow. Look at Japanese or Korean sunscreens for the latest in cosmetically elegant, light, non-sticky, instantly drying, non-greasy sunscreens!
• The best sunscreen is one you’ll use. If you have an SPF 30 sunscreen you love, use that!!

Common Questions and Discussion Topics

All about purging

What is purging?

To understand purging you need to first understand the skin cycle. The ELI5 version is that the organ generates new cells from the inside out to replace older cells that slough off. This is called turnover. For adults the cycle is roughly 6 weeks.

When you’re a child, your skin generates new cells more quickly, which is one major reason why kids are blessed with great skin and heal more quickly from injuries.

Retinoids accelerate the skin cycle, meaning that you generate new cells more quickly and your skin has an enhanced ability to heal. However, this also means that the acne cycle (impurities and bacteria underneath your skin coming to the surface as acne) accelerates as well. Typically, it may take a few weeks for the acne lesion that is formed in your skin to make its way to the surface and show up to your skin. So, purging is actually a phenomenon by which acne lesions that were already formed in your skin make their way to the top of your skin faster than they usually would, giving the impression that you’re getting new acne, when you’re actually just getting rid of ‘old’ ones faster. If purging is bound to happen to you, it cannot be avoided, nor should you want to avoid it, because you’re basically just dealing with your existing problems faster.

By the nature of its physiology, purging will usually last only for 6-8 weeks and will usually appear only on your usual breakout locations. If you’re getting new waves of acne in places you usually didn’t have them, or if those acne linger, or just keep coming again and again, that is likely not a purge. A purge is, by its definition, a one time thing. There is no ‘purging for 6 months’ or ‘second, third, sixth etc wave of purging’. That would likely be a consequence of irritation.

This does not mean that tretinoin will bear its full effects in 6-8 weeks, you can still get acne after that period like you used to, but it would most likely not be considered a purge. However, once tret shows its full effects after about 6 months, and your skin’s structure gets in order, it is important to keep maintenance of those effects and continue using tret. After that some people never have any acne again, and others have a reduced amount. It’s all individual.

Does everyone purge?

Purging is also actually not that common, people are just usually misinterpreting it. Here is a link to one study to support that, and the study defined purging as a 10 to 20% increase in inflammatory lesions, which is a significant but not an enormous difference.

Remember, irritation also causes breakouts. Retinoids are very irritating. THE SLOWER YOU GO, THE LESS LIKELY YOU ARE TO HAVE IRRITATION. Go as slowly as possible and focus on hydration and gentleness.

If you don’t have regular acne you are less likely to purge. Closed comedones may purge by becoming pimples.

What does a purge look like?

A purge should not be more than a 20% increase in breakouts. Closed comedones often come to the surface, so it can feel like your skin is getting much worse.

How long does the purge last?

It can last anywhere from a few days to 6-8 weeks. The purge should only be a 10-12% increase in your existing acne [10]. If your purge is worse than that or lasts longer than 6-8 weeks, it is probably not a purge and is irritation instead.  You may be sensitive to an ingredient in your tretinoin formula, but far more likely – you’re using it too much, too often. You can check up with your dermatologist to discuss what’s your best plan, changing the formulation or changing the regimen.

If I stop using Tretinoin will I purge again if I discontinue, and then restart it?

Maybe! This is difficult to predict.

All about flaking/peeling

How do I avoid flaking and peeling?

• Make sure your skin is completely dry when you apply tretinoin.
• A good moisturizer is key. Using a moisturizer actually improves tret outcomes especially a moisturizer with niacinamide. Vanicream Lite and Cerave are popular options.
• Vaseline or Aquaphor used on your tret ‘off’ nights can also really help prevent dryness. Pat on a very thin layer gently – don’t slather it, just apply a thin layer.
• Oil cleansing can work for many as a way to gently remove the excess skin. Get an emulsifying oil cleanser that will wash off easily.
• Consider skipping a night of tret if you have lots of peeling. Yes, that may slow down your progress by a few days but a damaged moisture barrier can take months to recover. Go slow. Skincare is a marathon.
• Make sure your routine is hydrating enough. Hydrating toners like those from Hada Labo can really help (Premium is the most popular since it has urea and 5 sizes of hyaluronic acid and is incredibly hydrating).

All about buffering

• Buffering does not impede function, and in fact, using a moisturizer actually improves tret outcomes especially a moisturizer with niacinamide. This is partly because it minimizes the irritating side effects and makes people better able to tolerate more applications of tretinoin.
• Having a healthy skin barrier is important for acne treatment. Everyone can benefit from a moisturizer (yes even if you have oily skin). Keep your skin moisturized and healthy to prevent breakouts and heal faster when you do break out.

Which formulation should I use?

Tretinoin is available in 3 primary vehicles: cream, gel, and gel microsphere. The cream is often preferred by those who have drier skin. The gel is good, although it does have alcohol but a solid routine can make up for it. The microsphere formulation really helps with irritation and the texture is gel-cream-like, but it may be less effective when buffering for some, so if you have extremely dry skin it may not work as well. The microform may also be much more photostable than the other two options. The “vehicle” in either formulation can trigger breakouts – so if you’re still breaking out after 4-6 months, consider switching types (gel → cream, cream → gel).

What percentage should I use?

• for anti-aging: A comparison between 0.025% and 0.1% shows similar improvement, but much less irritation for the lower percentage.
• Another study showed that 0.05% shows improvement over 6 months compared with/ 0.01%. It’s possible over many years the lower percentage would catch up to the higher percentage. Here is a picture of reasonable results to expect after 9 months on 51-year-old skin.
• for acne treatment: the lowest percentage that works is best. Higher percentages cause more irritation, and increased irritation causes acne.

Troubleshooting

Still lots of irritation after 5 months?

If you’re still getting tons of irritation, there are a few common issues we’ve seen. As with all skincare, your mileage may vary! Some have success doing everything “wrong”. This is just a troubleshooting guide, not rules set in stone. Contact your doctor if you’re very concerned! Here are some ideas:

• Did you jump into a really high percentage? Consider scaling back. 0.05% is pretty high at first. 0.1% is VERY high. It can help to start with 0.025% or 0.04%. The micro formulation is generally less irritating.
• Switch formulations. Some people experience breakouts triggered by a particular formulation. If you’re still breaking out after 4-6 months, consider switching types (gel → cream, cream → gel).
• Is your routine too irritating? Cut out ALL other actives and focus on hydration.
• Are you using it too *infrequently*? The skin has to go through the retinization process. That inherently involves some irritation. If you go too slow, your skin may actually never acclimate. If you’re only using tret a few times a week, try INCREASING your usage. At least 4x a week.
• Are you moisturizing enough? All skin needs moisture and hydration: check out the tips and links above for lots of info on a good routine.