The strength of a chemical peel is determined by a few factors including the percentage of the active ingredient, the acidity (pH) of the solution, and individual skin sensitivities. The concentration and pH are often listed on the product label. Keep in mind that the percentage is not equivalent for all ingredients, i.e. 20% TCA, 20% salicylic acid, and 20% glycolic acid are not the same strength. The pH is also a very important factor. The lower the number, the more acidic and therefore more intense the solution. A 50% lactic acid solution at a pH or 2.5 is stronger than a 50% lactic acid solution at a pH of 3.5.
The intensity of peels will vary within a classification. There are mild medium peels, strong medium peels, barely-there very superficial peels, almost-medium superficial peels, etc. Officially, there are 4 distinct and separate levels. Practically, it is a sliding scale.
Superficial peels can become medium strength peels from skin sensitivities that vary from individual to individual or from being left on for too long. Thinner skin around the eyes is also more sensitive than the rest of the face. Most body skin is more resilient than facial skin, but it can take longer to heal. Even though a certain concentration of an ingredient is categorized as a specific strength, you may experience more or less intense results. Keep this in mind when purchasing peels online, which are often marketed as a specific strength.
Repeating peels is common, especially with the lower strength peels. Don’t repeat a peel until the skin has entirely healed and is no longer peeling. The new skin exposed is more sensitive than normal, so it may react differently to the same peel.
Very Superficial Peels
These mild formulations can completely remove the first layer of skin, the stratum corneum, which is composed of dead skin cells and sebum. Many professionals consider them a form of heavy exfoliation rather than a true peel. They don’t remove live cells, but are still useful. In older skin, the stratum corneum becomes very uneven, and gives skin a dull texture. These peels also stimulate collagen production, increase cellular turnover, and can make skin thicker when used consistently over time.
You can achieve a very superficial peel from many home peels kits. Everyone should use these peels first before moving onto the stronger formulations. Many users can repeat these peels weekly or twice a week.
20% lactic or glycolic acid applied briefly.
Superficial peels can actually be irritating if not used correctly. These peels cause necrosis in part of or the entire epidermis. They can remove discoloration from sun damage, very fine lines, and soften wrinkles, but it will often take several treatments. These peels also stimulate collagen production and can increase skin thickness over time. This type of peel may need to be neutralized to avoid creating a deeper peeling effect that reaches the dermis. There usually isn’t a significant recovery period, although there is often some unsightly skin flaking that you must allow to heal on its own. You should let your skin completely recuperate before repeating this type of peel, typically 2-6 weeks. Most people will have to wait a few days to a week before resuming skin care products containing strong actives like retinoids and Vitamin C. Ideally, this is the strongest type of peel that should be performed in a home or spa.
30-50% lactic or glycolic acid. This strength of AHA can produce a medium peel if left on for more than a few minutes.
Jessner’s solution applied in 1-3 coats
Medium peels are actually quite serious. It is generally not recommended that you perform them at home because of the risk of infection and other complications including discoloration and permanent scarring. A spa setting isn’t ideal for this type of peel either, for the same reasons. Many doctors that perform this type of peel will often prescribe anti viral and anti biotic medication to be used before hand. Most people with dark skin tones shouldn’t use these peels, especially at home, because they are much more likely to experience permanent discoloration and skin tone irregularities.
The peel itself is uncomfortable, with some people experiencing pain. There can also be swelling, aggravating itching, and discomfort for the first few days afterward. It’s possible that a superficial peel will unintentionally reach the dermis and become a medium peel, so it’s helpful to learn more about them just in case you perform one unintentionally. Be aware that going to a doctor does not guarantee results. Because of the variation in human skin, it is difficult to determine how each individual will react. People have been scarred and burned under the care of a professional, and no aggressive procedure is without risk.
Medium peels are very effective because they cause necrosis in the entire epidermis and the upper part of the dermis, called the papillary dermis. The skin’s dermis is where the skin matrix, a network of interwoven collagen and elastin fibers, is stored and produced. Wrinkles, stretch marks, and scars are caused by irregularities and damage in the skin matrix. When a medium peel is performed, some of the irregular matrix is removed. As the skin recovers, the matrix heals in a more regular fashion. This type of peel can produce very noticeable results in a small amount of time. You’ll see full results after the following four months when collagen is finished regenerating. These peels are very effective at removing fine lines and wrinkles, as well as pitted acne scars and stretch marks. A lot of the improvement is seen right after the dead skin peels off, so it can be a very exciting experience.
It is helpful to use a skin-bleaching product such as hydroquinone for a month before a medium peel to reduce the risk of discoloration. The inflammation associated with these peels will often temporarily make the skin tone a bit darker.
After a medium peel, your skin will be covered with a brown or reddish layer of dead tissue. It is essential that you do not peel off any skin once it begins to flake. If you have large skin flakes, use a small pair of scissors to snip them off so they don’t catch and tear live skin. Peeling off skin prematurely is one of the biggest sources of scarring. The skin will feel tight, especially around the mouth. It can be difficult to eat and drink for a few days. Use a good moisturizer several times throughout the day. Avoid all sun exposure if possible, but if you must go out, use a moisturizer with a high SPF, wear a hat, and avoid the sunniest time of day, between 10:00 a.m. and 3:00 p.m. Do not use any makeup until all of the skin has peeled off. It usually takes one week for the peeling process to finish, but it can go up to two weeks, or even longer on some areas of the body, such as the arms.
The fresh skin exposed is very delicate, but is also much nicer looking than before. It is typically more sensitive to skin care actives, so you may need to use lower levels than you were using before. It can take a few months after a medium peel before the skin will behave normally. It is critical to use sun protection on freshly peeled skin. It burns easier and can also develop stubborn dark sunspots, even with non-burning sun exposure. Don’t repeat this strength of peel until the skin is behaving normally.
50-70% lactic or glycolic acid. Risk of complications increases with time left on.
Jessner’s solution applied in 3 or more coats
20% – 50% TCA
Layering different peels (i.e. 70% glycolic followed by 35% TCA, Jessner’s solution followed by 30% TCA, etc)
This strength of peel should not be attempted in the home or spa environment under any circumstances. It is typically performed in a doctor’s office under general anesthesia with pulmonary and cardiac monitoring. The active ingredient used in deep peels, called phenol, can be absorbed through the skin. The result can be cardiac arrest and there have been fatalities during this serious procedure. If you are going to have this type of peel done, do your research on your doctor. You should be close to emergency services in case complications arise.
Deep peels cause necrosis of the entire epidermis, the entire pappilary dermis, and penetrate to the reticular dermis. It is typically only used for severe scarring and totally unnecessary for most people. Recovery time for this type of peel can be 3 weeks or more.
Sometimes, phenol is used as a spot treatment on specific scars, sebaceous hyperplasia, or deep wrinkles while doing a medium peel on the rest of the face. This targeted approach is much safer than doing a full-face deep peel, while still giving excellent results.
88% phenol, Baker Gordon Phenol Formula