20 molecules — every one of them in a product this register has reviewed. For each: what it is, what it binds, how deep it acts, the strength the trials were actually run at, the range this register has recorded around it, and what it costs you in irritation.
5 of the 20 score 0 or 1 on the irritation index. The other 15 need a schedule.
Depth is the whole argument. A molecule that stops at the stratum corneum can change how skin looks this week and cannot change what it is made of. Only the third band decides lines.
Dead corneocytes in a lipid mortar. Everything optical happens here, and nothing structural does.
Live keratinocytes and melanocytes. Pigment is made here; turnover is set here.
Fibroblasts, collagen, elastin. The only layer where lines and laxity are actually decided.
SCROLL THE TABLE SIDEWAYS
| NO | ACTIVE | FAMILY | HOUSE | RANGE | IRRIT. | ONSET | GRADE |
|---|---|---|---|---|---|---|---|
| A-01 | Tretinoin | 0.05% | 0.001–0.1% | 6 | 8–24 WK | A | |
| A-02 | Tazarotene | 0.045% | 0.045–0.1% | 7 | 12 WK | A | |
| A-03 | Trifarotene | 0.005% | 0.005–0.005% | 8 | 12 WK | A | |
| A-04 | Hydroquinone | 4% | 4–12% | 5 | 8 WK | A | |
| A-05 | Azelaic Acid | 15% | 4–20% | 6 | 12 WK | A | |
| A-06 | Ivermectin | 1% | 0.88–1% | 2 | 4–12 WK | A | |
| A-07 | Metronidazole | 1% | 0.75–1.11% | 2 | 8–12 WK | A | |
| A-08 | Clascoterone | 1% | 1–1% | 1 | 12 WK | A | |
| A-09 | Roflumilast | 0.3% | 0.15–0.3% | 1 | 8 WK | A | |
| A-10 | Oxymetazoline | 1% | 1–1% | 3 | 3 H | A | |
| A-11 | Brimonidine | 0.33% | 0.33–0.33% | 5 | 3 H | A | |
| A-12 | Bimatoprost | 0.03% | 0.03–0.03% | 3 | 8–16 WK | A | |
| A-13 | Doxycycline 40 mg | 40% | 40–40% | 2 | 16 WK | A | |
| A-14 | Niacinamide | 4% | 4–5% | 1 | 8–12 WK | B | |
| A-15 | Fluocinolone Acetonide | 0.01% | 0.01–1% | 1 | 8 WK | A | |
| A-16 | Benzoyl Peroxide | 5% | 2.5–10% | 2 | 4–12 WK | A | |
| A-17 | Sarecycline | 100% | 60–150% | 2 | 12 WK | A | |
| A-18 | Tirbanibulin | 1% | 1–1% | 8 | 8 WK | A | |
| A-19 | Dapsone | 5% | 5–7.5% | 1 | 12 WK | A | |
| A-20 | Fluorouracil | 5% | 2–5% | 10 | 2–4 WK, THEN 1–2 MONTHS TO HEAL | B |
All-trans-retinoic acid
The molecule the whole category is measured against, and the only one a regulator has approved for facial wrinkles. Its own label denies, in capitals, that it reverses photoageing.
Tazarotene
The largest retinoid effect size in this register, attached to the worst price and the only outright pregnancy contraindication in the class.
Trifarotene
The first new topical retinoid molecule in decades, and the only one trialled on the trunk as a formal endpoint. Its label publishes irritation at both 7.5% and 65%.
Hydroquinone
The most effective topical depigmenting agent there is, the reason every compounded pigment formula exists, and a course rather than a regimen.
Azelaic acid
Does several useful things at once for skin that is inflamed and pigmenting simultaneously, which describes a great many people over thirty. The cheapest prescription in this register.
Ivermectin
The strongest single-agent evidence base in this register: two trials, 1,371 subjects, and 519 people followed for about a year.
Metronidazole
Decades of trial support and the class's standing question: an antibiotic dispensed monthly with no stated review point is a subscription, not a course.
Clascoterone
The topical anti-androgen — the same target as oral spironolactone, acting where the acne is. Irritation no worse than its own vehicle.
Roflumilast
The highest response rates in this register, the cleanest tolerability in it, and the worst price in it. All three at once.
Oxymetazoline hydrochloride
One of only two drugs approved for the redness of rosacea, and the weakest primary endpoint in this register — honestly measured and honestly published.
Brimonidine tartrate
The other approved treatment for rosacea redness, roughly twice as effective on paper — and the only molecule here whose label says the presenting complaint can come back worse.
Bimatoprost
The largest, least ambiguous cosmetic result in this register — alongside two harms that do not reverse when you stop.
Doxycycline
An oral tetracycline deliberately dosed under the antibacterial threshold, with a label that forbids using it for infection. The answer to every undosed antibiotic in this register.
Niacinamide
The one molecule in this register that appears in almost every compounded formula and is almost never the reason it works. Well tolerated, sensibly dosed, quietly useful.
Fluocinolone acetonide
The component that makes triple therapy tolerable, and the component that makes it a course. Every product built on this pattern needs a stop date.
Benzoyl peroxide
The standard cause of topical intolerance, and — sealed inside silica microcapsules — the second most effective rosacea treatment in this register. The molecule did not change.
Sarecycline hydrochloride
The second considered answer to the antibiotic problem in this register: keep the antibacterial activity, narrow the spectrum, and write the twelve-week limit into the label.
Tirbanibulin
Five days, then you stop. The shortest course in this register and the largest treatment difference after bimatoprost — for the photodamaged population every anti-ageing trial excluded.
Dapsone
The gentlest thing in this register's acne section, and the smallest effect in it. Its label is the only one anywhere here that reports a drug working differently in women than in men.
Fluorouracil
The only chemotherapy agent in this register, and the cheapest effective treatment in it. Two to four weeks of a deliberately damaged face, on a label that publishes no efficacy figure at all.
One reader gets a 12 months CoreAge Rx derm plan — the compounded, physician-reviewed subscription we take apart in the register. Worth $780. Leave an address and you are entered.
VALUE IS THE PUBLISHED $64.99/MONTH SUBSCRIPTION PRICE OVER TWELVE MONTHS, AS RECORDED IN R-10. NO PURCHASE NECESSARY. WE REVIEW COREAGE RX — WE DO NOT SELL IT.