A spent coffee grounds scrub: the base matters as much as the powder
Clinical trialSpent coffee grounds at 5% and 10% in 7 scrub basesConsumer test, then water loss measurementSample size and duration not given in the abstract
The ointment-based scrub showed no significant change in the skin barrier. The aqueous scrubs (cream and gel at 5%) disrupted it temporarily, with full recovery within 6 h after a hand cream2.
Antioxidant effects mostly in the laboratory
Review2026 reviewExtracts of coffee beans, leaves, fruit and grounds
In the laboratory, the extracts show antioxidant, anti-aging and photoprotective activities. In humans, trials are small and short, with modest improvements in hydration, elasticity and barrier function. The authors judge the evidence insufficient to make these products an evidence-based reference3.
Caffeine, chlorogenic acids and flavonoids
Review2025 reviewLeaves and beans of Coffea arabica
The review lists caffeine, chlorogenic acids and flavonoids. The leaves contain more of some phenolic compounds than the beans. The authors call for clinical trials to validate the benefits4.