The polysaccharides from Saccharina japonica can absorb and retain moisture more than hydroxyl acid, the commonly used skin moisturizer in clinical practice. Therefore, algal polysaccharides may be used in cosmetics as an additive. Agar and alginic acids are good hydrocolloids and emollient and used as cosmeceutical aid.

The Romans treated their joint pain by external application of kelp poultice prepared from Fucus vesiculosus. Roman ladies used a rouge extracted from Fucus vesiculosus for cosmetic purpose. In 3000 B.C. Shen Nung Pen Tsʼao Ching or The Divine Farmerʼs Materia Medica shared the therapeutic qualities of algae which was an outstanding contribution of Chinese scholar to algal research. It mentioned the use of marine algae to cure goiter. In the first century A.D. Pliny the Elder in Naturalis Historis recommended certain algae for gout. Dioscorides in his book De Materia Medica prescribed powder of Muscus corralinus for burns, diarrhea, heartburn, scurvy, skin rashes and abrasions. Galen in De Simplicibus noted that the mucilaginous substance present around the thallus of algae had remarkable properties of wound dressing. In the eighth century A.D., the ancient Polynesians made poultices from filamentous algae for bruises, cuts and inflammation. Chinese and Japanese monks recommended Gelidium amansii in case of fever attributed to stomach conditions.