This is a common question for those who are new to using a retinoid like Tretinoin and those who have adjusted to their strength.
Tretinoin is prescription-grade retinoid that smooths and exfoliates skin, while reducing oil production and acne, along with fighting sun damage. Tretinoin is a more effective retinoid than its cousin retinol, which is found in many over the counter photoaging products. Tretinoin will offer better improvement on skin tone, texture, and appearance. Tretinoin may generally be more drying, but can easily be offset by moisturizer and sunscreen.
Many individuals wonder what the right strength of Tretinoin is for his or her skin. Picking the right strength will create visible results and minimize side effects. While many may think that higher is better, it is important to review the history and science of Tretinoin before considering what is best for each individual’s skin.
Tretinoin comes in a variety of strengths or percentages. Initial studies of Tretinoin from the 1980s used Tretinoin 0.1% to evaluate the efficacy of Tretinoin for the treatment of photoaging and later studies evaluated Tretinoin 0.05%. While both were equally effective over a one year period, Tretinoin 0.1% was able to achieve cosmetic improvement in 6 months while 0.05% required closer to 12 months. Tretinoin 0.01% and 0.001% was also studied and neither were able to produce cosmetic improvement. Finally, Tretinoin 0.025% was compared to Tretinoin 0.1%, and it was found that both produced similar improvements in photoaging, with tretinoin 0.025% causing less side effects such as drying and irritation. All of these studies were performed using Tretinoin in a cream base.
These studies suggest that a higher strength Tretinoin may not always be necessary to achieve significant results. However, these studies do suggest that the strength of Tretinoin can affect how quickly improvement in the skin is noted. For example, Tretinoin 0.05% took several more months that Tretinoin 0.1% to achieve cosmetic improvement. Both appeared to have a similar side effect profile. Interestingly, Tretinoin 0.025% showed similar effects to Tretinoin 0.1%, at the 1 year mark. These studies looked at changes in the skin along with cosmetic improvement. Therefore, it could be concluded that while all strengths are effective, the time taken to achieve the cosmetic result can differ, as can the side effects.
Tretinoin strength is only one piece of the puzzle. Another important consideration is the formulation, or base that the product is made in. All skin products consist of an active ingredient, such as Tretinoin, and a vehicle, which makes it stable and can enhance its effectiveness. The choice of vehicle can be just as important as the choice of strength.
Once the ideal strength and formulation of tretinoin is achieved, it is reasonable to continue on that product. The ideal strength and formulation creates the desired cosmetic effect of improved skin tone and texture while minimizing side effects. There is likely no greater benefit to using a higher percentage or different vehicle, as studies have shown that they have similar outcomes over a different period of time.
Mukherjee S, Date A, Patravale V, Korting HC, Roeder A, Weindl G. Retinoids in the treatment of skin aging: an overview of clinical efficacy and safety. Clin Interv Aging. 2006;1(4):327–348.