Is polyester bad for your skin?

Polyester is a petroleum-derived plastic fabric that can irritate skin in several ways. Because it is essentially a form of PET plastic, polyester does not breathe well and traps heat and moisture against your body. This creates an ideal environment for bacterial growth, which can lead to rashes, irritation, and breakouts—especially in areas where the fabric sits tight against your skin like waistbands, sports bras, and leggings.

Beyond breathability, polyester is often treated with chemical finishes during manufacturing. These can include formaldehyde-based wrinkle resistors, antimicrobial agents, and synthetic dyes that may leach onto your skin, particularly when you sweat. People with sensitive skin or conditions like eczema often report flare-ups when wearing polyester garments for extended periods.

At ONDU, we curate brands that use natural and plant-based fabrics like Tencel, organic cotton, and merino wool. These fibers are breathable, moisture-wicking by nature, and free from the petrochemical residues found in polyester. Brands like Reprise Activewear make high-performance leggings and sports bras from 100% Tencel, proving you do not need plastic to get a great workout.