Either can work, mineral on non-mineral. Often folk look at “retin-a” OMG must use SPF 4,000. However, from what I’ve read the early stages of using retin-a cause a turnover of new skin also makes you susceptible, not only to the sun but even to wind (wind-burn). Meaning that one needs to be ultra-careful at the start of using retinoic acid.
I really don’t think it matters, though if one is in Korea, or as I will be, in Thailand and/or the Philippines I feel that I would need that SPF 126,000…… So much depends on where/what one is doing. Going shopping and intermittent exposures of short durations likely an SPF 30 is fine. In the Philippines SPF 50 is minimum. In the Philippines add an umbrella, and for me, literally try to avoid any exposure, yikes!
(I’ve had 3 basal cell carcinomas and one squamous cell carcinoma—from being proud of my suntan when I was a gardener at age 18—when “oh, the sun is good for you.”)
Some of the newer mineral ones seem impressive. There are questions about the chemicals in the chemical versions and quite frankly, I’ve had “ruined” days from burning eyes, even when I was careful about making sure I kept the chemical-based sunscreen away from my eyes. For me, that’s a strong, go-to mineral.
Try reading: “The Banned Sunscreen Ingredients and Their Impact on Human Health: A Systematic Review” See
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7648445/
Try asking your dermatologist, “why, is it systemically absorbed, and how much?”
My dermatologist told me that my rosacea is caused predominantly by demodex mites (skin mites) and so prescribed Metronidazole (the antibiotic-antiparasitic Flagyl). Uh, hmmm…what about the study that proved that demodex mites live quite happily surrounded by Flagyl? (Yes there is a study if one looks for it.) The reality is that nobody really knows why Metronidazole works—it’s fascinating. But, in medical school it was: “Rosacea is caused by demodex mites and Metronidazole kills them.” End of story, except that it’s simply not correct.
“The dose is the poison.” So, does using retin-a on the face + hands, or face + hands + arms + shoulders create systemic poisoning? From what I’ve read: “no.”
The percutaneous absorption of topically applied tretinoin and its effect on endogenous concentrations of tretinoin and its metabolites after single doses or long-term use
https://www.sciencedirect.com/science/article/abs/pii/S0190962297700598
“Conclusion: Minimal percutaneous absorption of tretinoin was obtained after its topical application in cream formulations. Neither single-dose nor long-term treatment with topical tretinoin formulations appeared to affect the endogenous levels of tretinoin or its metabolite”
“Mean plasma concentrations of tretinoin after 28 days of treatment with either tretinoin emollient cream or tretinoin cream were not significantly changed when compared with the corresponding endogenous concentrations before treatment.”
I’m not sure I’d do my back, legs, face, arms, hands…. But I have no issue using it on my face, neck and hands/arms. I do find that on my neck I only use it maybe 4/7 days.
Or
Today using Goodrx.com Tretinoin cream 20g 0.05% costs a whopping $17.35, less than $1/gram.
Use Goodrx.com or try pharmacychecker.com or find a reliable seller here from India who sells Sirolimus and buy a dozen 20 gram tubes of 0.05% for maybe $3 a tube (note: shipping will cost much more).
Do keep in mind that I always advise people to listen to their Provider (NP/PA/MD/DO) and not to some guy’s opinion on the internet….