The aim of the study was to investigate the potential of a fucoxanthin concentrate prepared from Phaeodactylum tricornutum as a wrinkle care cosmetic agent. The concentrate (up to 25 µg/ml) did not affect the proliferation of human fibroblasts. In addition, the concentrate significantly increased procollagen synthesis in the fibroblasts at 12.5 and 25 µg/ml; however, it significantly decreased the expression of matrix metalloproteinase (MMP)-1, MMP-2, and MMP-9 at 25 µg/ml. In a follow-up study, a wrinkle care cream containing 0.03% of fucoxanthin concentrate was prepared and tested in women (aged 35-50 years, n = 21) for 8 weeks. The cream was applied twice daily. Safety assessment of the cream was carried out visually. In addition, interviews were conducted to investigate if adverse events such as erythema, edema, scaling, itching, stinging, burning, tightness, or prickling had occurred. No symptoms that threaten skin safety were reported. Evaluation of wrinkles around the eyes using the replica method showed a statistically significant decrease in wrinkles at week 8. Moreover, skin moisture and elasticity increased significantly from week 4. These results suggest that the fucoxanthin concentrate has no adverse effects on the skin and can be used as an active ingredient in wrinkle care cosmetics.