Plants are a rich source of a wide variety of bioactive compounds that can be used for the preparation of cosmetics. Natural cosmetics with plant components such as vitamins, polyphenols, and alkaloids have become more and more popular. Alkaloids are important secondary metabolites in plants. They are known to possess therapeutic properties. Alkaloids can be used in the production of tonics, creams, lotions, face and hair masks, compresses for skin problems with numerous inflammations, and discoloration and antiaging products, as well as for reducing the formation of cellulitis. Alkaloids are also used in the production of ampoules for cosmetologists and aesthetic medicine doctors. However, at higher doses, they may exhibit toxic properties. Several studies have been carried out in evaluation of the activity of alkaloids from various plants for their use in cosmetics. This review describes alkaloids (caffeine, capsaicin, berberine, piperine, spilanthol, and anatabine) derived from various plants that are used in cosmetics, as well as their reported activities.