With the growth in the number of people searching for ways to improve personal care, the consumer finds the solution in cosmetic products. However, this demand is currently made concomitantly with the demand for products of natural origin, including seaweed. Algae, in their composition, are full of bioactive compounds with several applications. Therefore, their insertion in cosmetics is evidenced in the high number of scientific studies, which makes this natural resource potentially useful for the cosmetic industry. From this, a review was conducted with the aim of highlighting some of these active compounds and the latent applicability and versatility of others. In addition, the best way to add to the production of these substances while staying in alignment with green consumption, the design of biorefineries, and the promising production of macroalgae on a large scale using green technologies was sought.

Currently, the dilemma of antimicrobial resistance (AMR) worsens each year and poses a threat to global health. Macroalgae are potentially excellent sources of highly bioactive secondary metabolites, particularly useful for developing new functional ingredients, and might represent a promising reservoir of novel antimicrobial agents in the fight against AMR. This study was conducted to determine whether methanolic extracts from Gracilaria caudata (MeOHGc) macroalgae could serve as potential alternatives against human pathogenic bacteria. The antimicrobial activity of MeOHGc was evaluated using the agar disc diffusion method against gram‐positive Staphylococcus epidermidis and gram‐negative Escherichia coli . The chemical profile of the methanolic extract was assessed by qualitative phytochemical screening and gas chromatography–mass spectrometry (GC/MS) analysis. The results of phytochemical tests revealed the presence of sterols, terpenoids, tannins, and polyphenols. The GC‐MS profile of MeOHGc putatively identified two chemical constituents based on the pre‐established similarity index threshold (SI ≥ 90%): benzenepropanoic acid, 3,5‐bis (1,1‐dimethylethyl)‐4‐hydroxy‐methyl ester (SI: 96.8%) and phenol, 2,4‐bis (1‐methyl‐1‐phenylethyl)‐ (SI: 96.8%). The antimicrobial activity assay showed preliminary antibacterial activity against S. epidermidis at the tested concentrations, with no activity detected against E. coli . Our results place G. caudata as a potential source worth investigating for the development of new antimicrobial agents, and open perspectives for its further investigation as biomolecular sources of these compounds.