While here we mostly discuss longevity and biochemical, physiological, and metabolic ageing... we all know that the skin and the face are the reflection of whatever happens beneath. Our perception is so well-tuned to instantly extract information about the age and health of a person, just by looking at him/her. Which is what makes hiding signs of age through plastic/cosmetic intervention so hard...
In addition to lifestyle, supplements, and anti-ageing research in general, I've been quite immersed into the skincare and (skin) tissue health, structure, and ageing. Skincare generally addresses only the upper layers of the skin (epidermins, dermis). Most products and techniques (e.q. microneedling) are about these superficial layers and "collagen" production. I put collagen in quotes for a variety reasons.
First of all, collagen comes in multiple types, each is integrated into different structures of the body. Lots of "collagen" is not always good for the skin. Scar tissue is made out of collagen, yet we do not want it. Tissue changes associated with androgenic alopecia involve fibrosis, calcification, and excessive deposition of collagen. When the word "collagen" is used, we normally mean general structure and integrity of the tissue/organ. There are collagen types (e.q. VII and XVII) that are involved in structure rather than just plain mass (e.q. random: a diagram, another).
It was good to see research done on substances that were shown to increase their production (e.q. topical rapamycin and apocynin). I hope more will come on stem cell therapies, topical NAD+ modulators and their impacts skin in general.
Now, when we start going into deeper issues of facial ageing, we can't avoid the biggest one of them--the adipose tissue. Two layers of it that change with age and enormously contribute to our appearance. In addition to bones, these are the layers that instantly broadcast the information about our age to others. Even with a perfect skin, our faces would look old with adipose layer loss. Interestingly, there's a fair bit of research that shows that adipose tissue gets reduced in the areas affected by androgenic alopecia.
That brings me to a few points.
It's not that much we know about how to restore that subcutaneous fat! It's shockingly little, considering the massive cosmetics industry and the fact it's hard to find a greater desire than the desire to look younger.
Nuances aside (and not going into obvious such as nutrition), the most common approaches to "targeting" fat loss are fat grafting, and dermal fillers. One is basically a fat transplant. The other is a foreign substance like hylaronic acid, that just happens to not be destroyed by the body too quick and happens to mimic volume appearance. Nothing against either of them, it's an incredible feeling to see your face look younger in the mirror... even when you know it's a cover-up. After all, NAD+ boosters are also a cover up for methylation/epigenetic changes...
However, then there's a strange one I can't quite figure. Poly-L-lactic acid injections. A recognized product name is Sculptra. If we look for any info in the clinics who administer it, they call it a collagen booster. Instead of a foreign substance creating volume, your skin starts producing its own volume. The interesting part is the more official info, particularly by the FDA. On numerous occasions, you can see wording related to treating facial lipoatrophy. (originally it was a method of helping hiv patients to get some of their facial volume back...). Yet all the measurements from biopsies I can find only scan for collagen type I and III and general skin thickness increase. No mention of the adipose tissue beyond very strange and almost evasive semantics.
I am no expert and thus take my following comment with a big spoon of salt: some of the results on before/after photos look more like adipose tissue restoration than effects of collagen alone.
Thus I'd like to just ask if anyone here was involved with research or had personal experience. Or perhaps seen a paper that addresses my confusion about the effects.