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Look young

Each treatment is placed by how far testing in people has gone. A stage shows what has been studied, not whether it works. The counts behind every stage come from PubMed and ClinicalTrials.gov.

AllStay youngLook youngFeel young
4Stage 4 · Widely recommended

Daily sunscreen

A randomized trial found daily use slowed visible skin aging.

Over the counter · 82 human trials · 77 observational · 69 lab and animal

Tretinoin

Approved for sun-damaged skin after decades of trials.

Prescription · 107 human trials · 42 observational · 53 lab and animal

Minoxidil

Over the counter (scalp liquid or foam) · 206 human trials · 157 observational · 126 lab and animal

Finasteride

Prescription · 76 human trials · 87 observational · 62 lab and animal

Botox and other wrinkle-relaxing injections

Prescription injection, given in clinics · 279 human trials · 241 observational · 9 lab and animal

Hyaluronic acid fillers

Injected in clinics · 196 human trials · 233 observational · 15 lab and animal

Collagen-stimulating injections (Sculptra)

Injected in clinics · 82 human trials · 142 observational · 35 lab and animal

3Stage 3 · Large studies in people

Red light therapy

Small trials for skin, of mixed quality.

Clinics and home devices · 103 human trials · 112 observational · 38 lab and animal

2Stage 2 · Small studies in people

Collagen peptides

Over-the-counter supplement · 51 human trials · 9 observational · 159 lab and animal

Astaxanthin

Over-the-counter supplement · 14 human trials · 6 observational · 92 lab and animal

Retinol

Over the counter (creams and serums) · 30 human trials · 11 observational · 10 lab and animal

Vitamin C serum

Over the counter (serums) · 32 human trials · 17 observational · 16 lab and animal

Laser resurfacing (CO2 and fractional lasers)

Dermatologists and med spas · 249 human trials · 327 observational · 62 lab and animal

IPL photofacial (intense pulsed light)

Dermatologists and med spas · 93 human trials · 97 observational · 13 lab and animal

Microneedling (including RF microneedling)

Dermatologists, med spas and home rollers · 46 human trials · 55 observational · 8 lab and animal

Radiofrequency skin tightening (e.g. Thermage)

Dermatologists and med spas · 63 human trials · 88 observational · 19 lab and animal

Ultrasound skin lifting (Ultherapy)

Dermatologists and med spas · 39 human trials · 53 observational · 9 lab and animal

Chemical peels

Dermatologists, med spas and mild home peels · 47 human trials · 46 observational · 9 lab and animal

PRP for skin and hair (platelet-rich plasma)

Dermatologists, med spas and hair clinics · 92 human trials · 82 observational · 31 lab and animal

Stages come from published studies and trial registries. They show how far research has got, not how well something works. Companies cannot pay to change them. How stages and counts work.