What is the best-proven remedy for wrinkles: retinol or vitamin C?
Tretinoin (prescription vitamin A) has the best-proven evidence base against sun-related wrinkles; vitamin C has preliminary positive indications but has been studied far less. If you have sensitive skin or do not have a prescription, over-the-counter retinol is a reasonable alternative.
Tretinoin, the prescription form of vitamin A, has by far the strongest evidence base for wrinkles caused by sun damage. Eight controlled studies demonstrated superior efficacy versus a placebo, with a dose-response relationship: the higher the concentration, the greater the improvement. At 0.05% tretinoin, the likelihood of visible improvement was nearly twice as high as with placebo.
The downside of that potency is irritation. Redness, flaking and a burning sensation are common, and more severe at higher concentrations. Some people discontinue treatment early as a result. Over-the-counter retinol (also vitamin A, but in a weaker form) also shows improvement and causes less irritation, although it has been studied less extensively than tretinoin.
Vitamin C in a cream or serum (5% ascorbic acid) improved skin texture and elastic tissue in one double-blind study after 6 months, with good tolerability and hardly any side effects. That is a positive signal, but it rests on a single small study, making the evidence considerably thinner than for tretinoin.
There are no direct head-to-head comparison studies between vitamin C and tretinoin, so a fair head-to-head verdict is not possible. Anyone looking for the strongest evidence base should stick with tretinoin. Those with sensitive skin or who do not want to obtain a prescription may consider vitamin C or over-the-counter retinol, though these have been less thoroughly studied. There are also preliminary indications that combinations of vitamins A, C, E and B3 may enhance each other's effects, but this is not yet sufficiently substantiated for firm recommendations.
The evidence for tretinoin rests on eight controlled studies from which a Cochrane review pooled data. For vitamin C there is only one small double-blind study, which makes the evidence considerably thinner. The researchers in the Cochrane review noted that the evidence for vitamin C is limited. For over-the-counter retinol the evidence base is intermediate: positive, but based on fewer studies than for tretinoin.
Does retinol help against wrinkles?
Retinol demonstrably works against wrinkles and improves skin texture, although tretinoin is more potent for those who can or wish to obtain a prescription; people who experience irritation may consider bakuchiol as an equivalent alternative based on one small study.
Does a vitamin C serum help against pigmentation spots and ageing?
Vitamin C serums likely reduce pigmentation spots and early signs of ageing, but the studies are too small or lack control groups to draw firm conclusions. A combination serum that also contains niacinamide or tranexamic acid has the strongest evidence base, and should always be supplemented with daily sun protection.
Does microneedling work for wrinkles and scars?
Microneedling demonstrably works for wrinkles and acne scars, with radiofrequency microneedling being the variant with the strongest evidence base. Combining it with PRP can enhance results, but make sure you are well informed about side effects and choose an experienced practitioner.
Does taking collagen supplements actually work against wrinkles?
Taking hydrolysed collagen reduces wrinkles and improves hydration and elasticity, although the effects are modest and no established dose exists. Most studies used 2.5 to 10 grams per day for 8 to 16 weeks; marketing promises of spectacular skin rejuvenation are exaggerated.
Does liposomal vitamin C work better than regular vitamin C?
Liposomal vitamin C reaches higher concentrations in your blood than the regular form, but whether that actually does anything for your health has not yet been proven. Until it is, the higher price is difficult to justify, unless you experience stomach complaints with high doses of regular vitamin C.
Does vitamin C actually help against a cold?
Taking vitamin C daily does not protect most people against colds, but does make a cold slightly shorter and milder. If you train intensively, the benefit is greater. Anyone who really wants an effect during a cold is better off looking at zinc.