Molecular formula: C8H10N4O2
Molecular weight: 194.19 g/mol
IUPAC name: 1,3,7-trimethylpurine-2,6-dione
CAS number: 58-08-2
EC number: 200-362-1
Caffeine is a naturally occurring methylxanthine, which belongs to the purine class of molecules. The purines are significant components of important biological molecules such as deoxynucleic acid (DNA), ribonucleic acid (RNA), adenosine triphosphate (ATP), guanine-5-triphosphate (GTP), and nicotinamide adenine dinucleotide (NADH). Caffeine is found in the leaves, nuts, and seeds of a variety of plants from tropical regions of the world. Upon ingestion, caffeine acts as a stimulant of the central nervous system by binding with adenosine receptors (due to its structural similarity). As a result, adenosine is not able to bind with its receptors and carry out some of its physiological roles, such as the regulation of sleep and arousal.
In skin care and the dermatological area, researchers have discovered a number of beneficial effects of caffeine.1 Due to its stimulation of lipolysis (the breakdown of lipids), caffeine is found in many anti-cellulite products. Caffeine also increases the microcirculation of the blood. It has been shown to help stimulate hair growth, which is believed to be a result of its inhibition of 5-alpha-reductase activity.2 In addition, caffeine has antioxidant properties and has been shown to provide protection of skin from UV radiation. Moreover, studies have shown that nonmelanoma skin cancer incidence is lower in individuals that consume caffeinated coffee.3
Melting point: 238 °C
Solubility: 1 g/46 mL H2O; 1 g/ 66 mL ethanol
pH: 1% (w/w) caffeine in H2O – pH 6.9
1. A. Herman and A.P. Herman, Caffeine’s mechanisms of action and its cosmetic use, Skin Pharm. Physiol., 26, 8-14 (2013).
2. M.J. Visconti, W. Haidari, and S.R. Feldman, Therapeutic use of caffeine in dermatology: A literature review, J. Dermatol. Dermatol. Surg., 24(1), 18-24 (2020).
3. Y-F Li et al., Caffeine protects skin from oxidative stress-induced senescence through the activation of autophagy, Theranostics, 8(20), 5713-5730 (2018).
8. M.J. O’Neil, The Merck Index, 15th ed., The Royal Society of Chemistry: Cambridge, UK (2013).