What retinal actually is, in one paragraph
Every over-the-counter vitamin A product is a precursor. Skin enzymes convert what you apply into retinoic acid, and each conversion step loses some of the material along the way. Retinyl esters need three steps and are the weakest of the family. Retinol needs two. Retinal needs one. Tretinoin is retinoic acid itself, needs none, and is prescription-only for exactly that reason. Fewer steps means more of what you applied arrives as the active form — which is the entire argument for paying more for retinal. Our retinol vs retinal comparison works through the trade-offs in more detail, and retinol vs retinoid maps the whole family.
How to read the numbers
This is the part that trips people up, so it is worth being blunt: a retinal percentage and a retinol percentage are not the same unit. A stated 0.1% retinal is not “a fifth as strong” as a stated 0.5% retinol. Because retinal is further along the conversion chain, comparable results tend to come from substantially smaller numbers — which is why the retinal ladder tops out around 0.2% while the retinol ladder tops out at 1%.
Treat the two scales as separate. If you are moving over from retinol, do not try to match your old number; start at the bottom of the retinal ladder regardless of how comfortable you were on retinol, and rebuild frequency from two nights a week. Published tolerance work has found retinol and retinaldehyde to share a low irritation potential relative to retinoic acid, which is reassuring — but “lower than tretinoin” is a wide bracket, and your first fortnight is still an adjustment period.
The rungs, roughly
- 0.05%— entry. Where anyone new to retinal should begin, including people with years of retinol behind them.
- 0.1%— the middle. A real step up, and where most people settle if they get on with the category.
- 0.15–0.2%— the top of what is commonly sold. Potent. Worth reaching only after months at a lower rung without reaction.
Who should buy retinal instead of retinol
Retinal makes sense in three situations. The first is a plateau: you have been using a stated-strength retinol near-nightly for six months or more, you were seeing change, and now you are not. The second is speed — if you have a specific horizon and want the most efficient over-the-counter option, the shorter conversion path is a legitimate reason to pay more. The third is the awkward middle ground between over-the-counter and prescription: people who want more than retinol offers but do not want, or cannot easily get, a tretinoin prescription. Our retinol vs tretinoin page covers what crossing that line involves.
Retinal is the wrong buy if you are new to retinoids, if your skin is currently irritated or compromised, or if your budget only stretches to one bottle and you would be choosing the retinal over sunscreen. It is also unnecessary if you have not yet given a good retinol a fair run — most people who conclude retinol “did not work” used it inconsistently for six weeks, which is a timeline problem rather than a molecule problem.
How to start retinal without a setback
Start at the bottom rung. Not the one that matches your retinol number. The bottom. Two nights a week for the first month.Add a night only when the current frequency has been comfortable for two full weeks — the schedule in our how often guide applies unchanged. Buffer generously. Retinal formulas tend to be lighter than the cushioning night creams people move from, so the moisturizer over the top is doing more work than it used to. The sandwich method is a reasonable starting point for the first fortnight.
Nothing else new for a month.No acids, no strong vitamin C in the same routine, no new exfoliating cleanser — see the layering guide for what combines safely. Sunscreen every morning, without exceptions. Sun sensitivity rises with retinoid potency, and retinal is more potent than what you were using.
Storage matters more here
Retinal is less stable than retinol and noticeably less stable than adapalene. Light and air degrade it, which is why the better products in this category come in opaque tubes, pumps or airless packaging rather than dropper bottles or jars. Keep it closed, keep it out of a sunny bathroom, and do not buy a bottle so large you will still be working through it a year from now — a smaller bottle you finish is worth more than a big one that oxidizes on the shelf. If a retinal product has turned noticeably darker or smells rancid, it is done.
What we did not include
We left out the growing number of unbranded retinal serums with no stated strength, no formulation detail and no track record. The whole reason to move to retinal is precision; buying an anonymous one throws that away and leaves you paying a premium for a guess. We also left out combination products where retinal is one of eight marketed actives — if a formula is competing for your attention with five other names on the front of the box, the retinal is rarely the star of the ingredient list.