Retinyl palmitate is a natural product, a phenyl analogue of vitamin A or retinol. Chemically, it is an ester produced by the condensation of hexadecanoic acid with retinol. 

It takes the form of a fine white to amber-coloured powder or an amber-coloured transparent oily liquid.

Medical

Retinyl palmitate is the most stable and common enhancer of vitamin A, sugar, wheat flour and monosodium glutamate currently used. It is used to enhance transdermal and dermal delivery of drugs (1). It has antioxidant and anti-cancer properties (2).

Cosmetics

Retinyl palmitate is used as an anti-ageing agent in body and face creams, as it is able to regulate the growth of epithelial cells and their differentiation by increasing collagen production. It also improves the keratosis of the skin when it is damaged in some way by UV rays (3). It also acts as a penetration enhancer.

The suggested amount for inclusion in cosmetic formulations is 0.5%-5%.

Safety

There is no evidence that Retinyl palmitate can cause cancer despite a press campaign and this study explains why (4).

Retinyl palmitate studies

Typical commercial product characteristics Retinyl palmitate

Appearance	Fine yellow powder
Boiling Point	546.51°C    607.5±24.0°C at 760 mmHg
Melting Point	28-29℃
Density	0.9±0.1 g/cm3
Refractive index	1.511
Flash Point	79.7±21.2°C
Loss on Drying	≤5.0%
Ash	≤5.0%
Particle size	95% pass 80 mesh
Heavy metals	10ppm
Arsenic	2ppm
Lead	2ppm
Cadmium	2ppm
Total plate	10,000cfu/g Max
Yeast & Mold	1,000cfu/g Max
PSA	26.30000
LogP	14.83
Vapour Pressure	0.0±1.7 mmHg at 25°C
Index of Refraction	1.508
Storage	2-8°C
Safety

• Molecular Formula  C₃₆H₆₀O₂
• Molecular Weight  524.9   
• Exact Mass   524.459351
• CAS  79-81-2
• UNII   1D1K0N0VVC 
• EC Number   201-228-5
• DSSTox Substance ID  DTXSID1021241
• IUPAC  [(2E,4E,6E,8E)-3,7-dimethyl-9-(2,6,6-trimethylcyclohexen-1-yl)nona-2,4,6,8-tetraenyl]
• InChI=1S/C36H60O2/c1-7-8-9-10-11-12-13-14-15-16-17-18-19-25-35(37)38-30-28-32(3)23-20-22-31(2)26-27-34-33(4)24-21-29-36(34,5)6/h20,22-23,26-28H,7-19,21,24-25,29-30H2,1-6H3/b23-20+,27-26+,31-22+,32-28+ 
• InChl Key      VYGQUTWHTHXGQB-FFHKNEKCSA-N
• SMILES   CCCCCCCCCCCCCCCC(=O)OCC=C(C)C=CC=C(C)C=CC1=C(CCCC1(C)C)C
• MDL number  MFCD00019414
• PubChem Substance ID    329751039
• ChEBI  17616
• RXCUI 35406    
• NSC  758478 
• RTECS   VH6860000
• NACRES  NA.24   
• Beilstein   1917366
• NCI  C1217

Synonyms:

• Vitamin A palmitate
• all−trans−Retinol palmitate
• [(2E,4E,6E,8E)-3,7-dimethyl-9-(2,6,6-trimethyl-1-cyclohexenyl)nona-2,4,6,8-tetraenyl] hexadecanoate
• Retinylpalmitat

References______________________________________________________________________

(1) Paolino D, Lucania G, Mardente D, Alhaique F, Fresta M. Ethosomes for skin delivery of ammonium glycyrrhizinate: in vitro percutaneous permeation through human skin and in vivo anti-inflammatory activity on human volunteers. J Control Release. 2005 Aug 18;106(1-2):99-110. doi: 10.1016/j.jconrel.2005.04.007. 

(2) de Carvalho Melo-Cavalcante AA, da Rocha Sousa L, Alencar MVOB, de Oliveira Santos JV, da Mata AMO, Paz MFCJ, de Carvalho RM, Nunes NMF, Islam MT, Mendes AN, Gonçalves JCR, da Silva FCC, Ferreira PMP, de Castro E Sousaa JM. Retinol palmitate and ascorbic acid: Role in oncological prevention and therapy. Biomed Pharmacother. 2019 Jan;109:1394-1405. doi: 10.1016/j.biopha.2018.10.115.

(3) Antoniou C, Kosmadaki MG, Stratigos AJ, Katsambas AD. Photoaging: prevention and topical treatments. Am J Clin Dermatol. 2010;11(2):95-102. doi: 10.2165/11530210-000000000-00000. 

(4) Wang, S. Q., Dusza, S. W., & Lim, H. W. (2010). Safety of retinyl palmitate in sunscreens: a critical analysis. Journal of the American Academy of Dermatology, 63(5), 903-906.