SHEET /vs/adapalene-vs-tretinoin · COMPARISON
Adapalene vs Tretinoin: what is the difference?
How they differ
from source
Tretinoin is retinoic acid, the active form of vitamin A, and adapalene is a lab-designed molecule built to act at the same retinoic acid receptors without being a vitamin A molecule at all. Tretinoin, C20H28O2 at 300.4, has a long chain of alternating double bonds that light and air break down, while adapalene, C28H28O3 at 412.5, replaces it with rigid aromatic rings and is far more stable. Adapalene binds mainly two of the three receptor types. That stability is part of why adapalene, as Differin, became the first retinoid sold without a prescription in the United States in 2016, while tretinoin, as Retin-A, remains prescription only there.
Side by side
| Adapalene | Tretinoin | |
|---|---|---|
| Formula | C28H28O3 | C20H28O2 |
| Molecular weight | 412.5 g/mol | 300.4 g/mol |
| Family | Retinoids | Retinoids |
| Everyday group | OTC medicine | Prescription medicine |
| Functional groups | Carboxylic Acids, Aromatics, Ethers | Carboxylic Acids |
| GHS signal wordThe supplier-filed hazard label, not a statement about ordinary use. | Warning | Danger |
| Oral LD50A single acute animal measure. It ranks nothing about human safety. | not recorded | 1,960 mg/kg (oral, rat) |
| CAS number | 106685-40-9 | 302-79-4 |
| PubChem CID | 60164 | 444795 |
Common questions
- What is the difference between Adapalene and Tretinoin?
- Tretinoin is retinoic acid, the active form of vitamin A, and adapalene is a lab-designed molecule built to act at the same retinoic acid receptors without being a vitamin A molecule at all. Tretinoin, C20H28O2 at 300.4, has a long chain of alternating double bonds that light and air break down, while adapalene, C28H28O3 at 412.5, replaces it with rigid aromatic rings and is far more stable. Adapalene binds mainly two of the three receptor types.
- Is Adapalene bigger than Tretinoin?
- Adapalene is the heavier molecule, 412.5 g/mol against 300.4 g/mol for Tretinoin. Adapalene is C28H28O3 and Tretinoin is C20H28O2.