Overview on retinoids

[brutalmog]

Retinoids work by attaching to retinoic acid receptors in the skin, and there are two main families (RARs and RXRs) with three subtypes: alpha, beta, and gamma. These receptors stimulate the skin's production of skin cells and regulate inflammation. RAR gamma is the most common retinoid receptor in the skin.


All of them are useful for anti-aging, as they all stimulate the skin to speed up skin cell turnover and produce collagen. Even if they weren't explicitly studied for that, by logic and their mechanism of action, you can determine it would help. Same with acne. They can all help acne, but you would want a retinoid over retinol when treating moderate acne.


Retinol esters, retinol, retinal are under the umbrella of the family of retinoids. But usually retinoids are used to refer to the active state ones like Adapalene, Tretinoin, etc.


Good overview, with data on retinol and retinal as well as tretinoin: https://www.ncbi.nlm.nih.gov/


pmc/articles/PMC2699641/


Higher isn't better with Tretinoin for anti-aging:

Two concentrations of topical tretinoin (retinoic acid) cause similar improvement of photoaging but different degrees of irritation. A double-blind, vehicle-controlled comparison of 0.1% and 0.025% tretinoin creams - PubMed

Tretinoin 0.1% and 0.025% produce similar clinical and histologic changes in patients with photoaging, despite significantly greater incidence of irritation with the higher concentration. The separation between clinical improvement and irritation suggests that mechanisms other than irritation...

pubmed.ncbi.nlm.nih.gov

Adapalene vs Tretinoin for photodamage: https:// pubmed.ncbi.nlm.nih.gov/30105991/

ОТС

• Retinol esters (like retinyl palmitate / propionate)
  very weak, requires three steps conversion to retinoic acid. More useful as an antioxidant than as a retinoid. Don't expect this to really "treat" anything.
• Retinol requires two steps conversion by the skin into the active form, retinoic acid
• Retinal requires only one step to reach that active state
• Adapalene is in the active state ready to bind to receptors in the skin (it has higher selectivity towards RAR beta and gamma receptors unlike tretinoin. It is less irritating than Tretinoin. It was developed to treat acne but is also effective for photoaging (see study above) 0.1% is otc in some countries, prescription in others like Canada and EU; 0.3% is precription regardless

Prescription all are in active state, no conversion needed

• Tretinoin binds to all three RARs: alpha, beta, and gamma retinoic acid receptors. It is the most effective for sun damage. It is considered the gold standard for anti aging due to the sheer number of studies on it. But it is also great for acne and quite a few skin diseases. It comes in many forms and types of encapsulation (0.025%, 0.05%, 0.06%, 0.08%, 0.1%) it can be quite irritating.
• Tazarotene binds to all three members of the retinoic acid receptor (RAR) family: RARa, RARb, and RARg, but shows relative selectivity for RARb, and RARg; it also shows a proclivity for RXRs. It's been shown to be very effective for male acne, but is even more irritating than tretinoin. Helpful for Psoriasis. (0.045%, 0.05%,
  0.1%)
• Trifarotene is the first novel topical retinoid approved for the treatment of facial and truncal acne in 20 years this is what I use Trifarotene has a 20 times greater selectivity for RARg over RARa and RARb, whereas tretinoin and adapalene have less specificity. Trifarotene is unique because it is the only topical retinoid that selectively targets RAR-gamma (to a 20x greater selectivity) and it is the first topical treatment studied and proven to treat both facial and truncal (chest, shoulders and back) acne. "In its Phase 3 trials, trifarotene demonstrated rapid improvement after one week on the face and two weeks on the trunk. Clinical improvement continued over 52 weeks, with treatment success
• has a 20 times greater selectivity for RARg over RARa and RARb, whereas tretinoin and adapalene have less specificity. Trifarotene is unique because it is the only topical retinoid that selectively targets RAR-gamma (to a 20x greater selectivity) and it is the first topical treatment studied and proven to treat both facial and truncal (chest, shoulders and back) acne. "In its Phase 3 trials, tritarotene demonstrated rapid improvement after one week on the face and two weeks on the trunk. Clinical improvement continued over 52 weeks, with treatment success achieved in more than 65 percent of patients on the face and the trunk." (0.005% is the only available strength; brand name Aklief, no generic yet) the base of this is very unique and less irritating. It even has Panthenol to soothe! I have seen it work faster than the Adapalene 0.1% and Tretinoin 0.05% I used in the past.
  
  
  Quote from: https://practicaldermatology.com/ articles/2020-apr/an-update-on-the-use-of-trifarotene-for-the-treatment-of-acne