People ask me what sunscreen I use more than they ask me anything else about my skin. The answer disappoints them. Not much, and not most days.
I put something on when I am going to be outside for a real stretch, in real sun. Otherwise I get on with my day, and I have done for years.
That is not carelessness. It is what I think the evidence supports, and it is what I formulate around.
What sunscreen actually does
Sunscreen is a filter. It absorbs or scatters UV before it reaches your skin, and for the hours you are genuinely exposed, it works.
What it does not do is make skin resilient. It sits on top and intercepts. The moment it wears off, or you miss a patch, or you reapply an hour late, your skin is doing the work on its own with whatever reserves it has.
So the question that matters is not only how much UV you block. It is what your skin does with what gets through.
That second question is the harder one to sell, because resilience does not reduce to a number on the front of a bottle. SPF is one figure and it fits neatly on a label. An antioxidant reserve, an intact barrier, and a repair system that works while you sleep do not.
The exposure most people actually get
The advice we have all absorbed was built for a different pattern of living.
Most of the people I know are outside for a walk to the car, a walk from the car, and ten minutes with a coffee. That is not a beach holiday. Treating those two situations as the same thing is how a reasonable precaution turned into a daily ritual applied to skin that was mostly indoors under artificial light.
If you work outdoors, or you are at altitude, or you are on the water, that is a genuinely different conversation and you already know it.
What is in the bottle
Chemical filters and mineral filters are not the same thing and are not tested the same way.
Oxybenzone, one of the most widely used chemical filters, is absorbed through the skin into the bloodstream. FDA studies found plasma concentrations well above the threshold at which the agency asks for further safety data, after a single application. That does not make it a poison. It does mean it has been in daily use for decades on a level of evidence that would not clear the bar today, and several jurisdictions have banned it outright over reef damage.
Zinc oxide behaves differently. It largely stays where you put it.
I use mineral, on the days I use anything.
The thing nobody tells you
A long list of common medications are photosensitising. They change how your skin responds to UV, and they can produce burning, rashes and pigment at exposure levels you would otherwise handle without noticing.
Tetracycline antibiotics like doxycycline. Some diuretics, and hydrochlorothiazide in particular has been associated with increased skin cancer risk in large studies. Certain NSAIDs. Retinoids. St John's Wort.
If you are on any of those, your relationship with the sun has changed and it is likely that nobody mentioned it to you. That is worth knowing far more than another reminder to reapply.
Sun avoidance is not free either
A Swedish cohort followed around 30,000 women for twenty years and found that women who avoided sun exposure had roughly double the all cause mortality of those with the highest exposure. The authors were careful about what that does and does not prove, and so am I. It is not a licence to burn.
But it does mean the trade is a trade, with something on both sides of it, and the public message has only ever described one side.
What actually makes skin handle daylight well
Your skin has its own defenses and they are not metaphorical.
Melanin, which is a UV absorber your body manufactures on demand. An antioxidant network including vitamins C and E, glutathione and CoQ10, which neutralises the free radicals UV generates. DNA repair enzymes that work through the night. A barrier that either holds together under stress or does not.
Every one of those depends on what you have to spend. Skin that is depleted, inflamed, over-exfoliated and short on lipids is skin with nothing in reserve. Skin that is well fed and intact copes with a walk to the car without any drama at all.
Protection was always meant to sit on top of this. We built a whole category that skipped the part underneath.
It is also what I formulate for. F19 Just Fruit Antioxidant Serum, from $82, is fresh fruit polyphenols built for exactly this, working on what does get through. F20 Rose Ceramide Barrier Cream, from $71, is the barrier half of the same argument. Neither of them has a number on the front, and both of them are the part that was skipped.
Where I go further than the evidence
Everything above I can point to.
What follows is what I think. Belief, not proof.
I think the fear has been overcorrected. I think we have taught a generation to treat ordinary daylight as a hazard, and that the cost of that has not been counted honestly, in vitamin D, in the metabolic and mood effects of light, and in the strange modern idea that a body is safest when it is never exposed to the conditions it evolved under.
I also think we have been sold a chemical solution to a problem that is partly a resilience problem, by an industry with no interest in the second half of that sentence.
I cannot prove that. Nobody is going to fund the study. So I am telling you it is my opinion, and you should weigh it as one.
What I actually do
I get sun most days without thinking about it.
If I am going to be out in strong sun for more than an hour, I cover up, and if that is not practical I use a mineral filter.
I eat for my skin and I keep my antioxidant intake high, which is neither glamorous nor optional.
And I do not spend any part of my day afraid of a window.
If you have pigmentation you are actively trying to fade, that is a different situation. Sun is the signal that starts pigment, so while you are working on a spot, sun is working against you. Shade, a hat, and cover when you are out in it for a stretch. The dark spots piece goes through the whole mechanism.
The rest of the time, build the skin. It is better at this than you think, when you give it something to work with.
