I do face many patients like yourself with similar questions regarding how to use topical medication creams they are given.
Firstly, I believe it is important to obtain these creams from a doctor who is familiar with using them. Your doctor and/or clinic should be able to identify the type of pigmentation you have, whether they are sun spots (lentigo), melasma, post-inflammatory hyperpigmentation, or freckles, for example, and then prescribe you the appropriate medication cream, as not all pigmentation respond with equal efficacy to Kligman's formula.
I note that you also mentioned you have acne. Personally, I prefer not to combine tretinoin and differin (adapalene) together at the same time as both are in the class of medication called "retinoids". Both tretinoin and differin may be used for anti-aging, pigmentation and acne. While there is no strict rule and I know of some patients who do well alternating these 2 creams daily, using both tretinoin and differin at the same time can increase your risk of skin dryness, redness, peeling and sun sensitivity. I would suggest you bring this up to your doctor, who may then assess which is your predominant issue and advise accordingly.
Finally, I recommend all my patients to cleanse and moisturise their face daily as part of a basic skincare routine. Happy new year and hope your skin continues to improve!
Best regards,
Dr. Joanna Chan
