Multiple studies published by the Journal of the American Medical Association show the effectiveness of vitamin A for addressing many skin problems. Topical use of vitamin A is understood to hasten cell maturation and correct oxidation damage. New cells are healthier, and rapid turnover in cells reduces potential for further damage.
Like every vitamin, vitamin A is biologically active in multiple forms. Each form has its own unique characteristics and activities. A comparison of Retina-A, otherwise known as retinoic acid, with retinol requires an overall understanding of vitamin A forms.
Metamorphosis of Vitamin A
This fat-soluble and essential vitamin is obtained through food. In vegetables and other sources, it primarily exists as an ester called retinyl palmitate. Most vitamin A is stored in the body in this form. It is fairly stable and not very active.
The body first converts retinyl palmitate to retinol for use. This is a two-way conversion from ester to alcohol, and it is reversible. This means any unused retinol is converted back into the ester form for storage. Retinol is most commonly found in OTC skin-care products.
The body can further transform retinol into retinaldehyde. This form is found on the retina of the eye. This is also a two-way conversion. Unused retinaldehyde is converted back into retinol and then into the ester form. This version is sometimes found in skin-care products due to its increased reactivity versus retinol, and the reduction in side effects versus retinoic acid.
The final transformation of vitamin A is to retinoic acid. This form cannot be reversed to other forms. It is the only form active in the skin. It is the most powerful and potentially irritating version of vitamin A.
OTC or Prescription?
OTC topical creams and ointments never contain the more powerful retinoic acid. Only prescriptions, such as Retin-A, are allowed to include it at standardized doses. How do you know which to use for a particular problem? It comes down to your individual skin sensitivity and the desire for rapid results.
Retinoic acid causes more side effects. Any amount not used by the skin simply sits in the dermal layer causing irritation. It is powerful and acts quickly, but time is needed to obtain a proper dosage.
Retinol causes far fewer side effects due to its inactivity on the skin. Dermal cells must convert retinol to retinaldehyde first. Only a useful amount of retinaldehyde is converted into retinoic acid, and the rest is back-converted into the ester form for storage.
Any topical application of vitamin A can result in irritation. It may make matters worse by thinning the dermal layer and aggravating inflammatory conditions, such as rosacea and acne. Correct dosage is a necessity with any form due to the potential for irritation.
The best approach for either Retin-A or products containing retinol is to start with a small dose and increase slowly. Application once every two or three nights provides early alert of extreme sensitivity. Limiting applications to the evening prevents sun damage associated with topical vitamin A. Either form of the vitamin is effective, but fast results require Retin-A.