Both Retinoic acid (Tretinoin) and Adapalene (Differin) are Retinoids, a group of chemical compounds that have some form of Vitamin A related activity.
They are involved in treatment of acne and prevention of new acne.
They are similar because they bind to retinoic acid receptors on keratinocyte cells in the skin but different retinoids bind to different receptors which explain the slight differences in action.
They increase cell turnover but Tretinoin does so more potently (targets more receptors) , which is how it smooths wrinkles, improves texture and reduces pigmentation. Differin is milder and better suited to target acne alone. However, there was a study that showed significant improvement of wrinkles with Differin [1].
Tretinoin works faster with onset of effect as early as 2-3 weeks but you may require up to 6 weeks of treatment to see consistent benefit. This is compared to 8 to 12 weeks of Differin use.
Tretinoin comes in different strengths 0.01%, 0.025 and 0.05%. And is available in both gel and cream forms.
Gel formulations are recommended for patients with oily skin versus creams for dry or sensitive skin.
Differin is mainly sold as gel form. It comes in both 0.1% and 0.3% strengths with 0.1% the more commonly used by far.
0.1% Differin offers comparable efficacy to Tretinoin 0.025% but is less irritating [2].
Tretinoin does allow for more flexibility in prescribing to different skin types ( dry versus oily) and tailor the concentration depending on the patients skin and clinical response.
Depending on your skin type and the concerns, speak to your Doctor to choose the appropriate product for your needs.
Regards
Dr Mark Lim
References:
1.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. doi:10.2147/ciia.2006.1.4.327
2. Tu P, Li GQ, Zhu XJ, Zheng J, Wong WZ. A comparison of adapalene gel 0.1% vs. tretinoin gel 0.025% in the treatment of acne vulgaris in China. J Eur Acad Dermatol Venereol. 2001;15 Suppl 3:31-6. doi: 10.1046/j.0926-9959.2001.00010.x. PMID: 11843231.
