Always read and follow the care instructions and any warnings on the garment label. And, follow the General Rules for washable fabric stain removal.
This is a real tough one, and may be permanent. It can penetrate into the fabric and when it dries coats the fibers in a harden "plaster." Unless there are instructions on the product label, you can try specific stain removal products available at the grocery or drug store, such as Carbona's "Stain Devils®" or take the stain to your dry cleaner and tell them to treat it as a paint stain.
MEN'S HORIZONTAL DR. COOL SHIRT
This shirt is constructed using Coolcore's patented chemical-free moisture and sweat activated material to make sweat work for you. Rather than a simple wicking technology, the material delivers three distinct functions: wicking, moisture circulation, and regulated evaporation to reduce the fabric's surface temperature by up to 30%. Unlike other workout shirts Dr. Cool is chemical-free so that cooling benefits last the life of the shirt. Learn more about this technology. Shop for this technology>
WOMEN'S LONG SLEEVE CREW NECK
This women's long sleeve crew neck shirt is the ideal workout shirt for any activity. Dr. Cool uses a patented chemical-free cooling material designed by Coolcore to you comfortable, dry and cool for maximum performance. The moisture and sweat activated material delivers three distinct functions: wicking, moisture circulation, and regulated evaporation to reduce the fabric’s surface temperature by up to 30%. Learn more about this technology. Shop for this technology.