Alas, yes.. time, friction, sweat and tears all play a part in reducing the water repellant tendancies of your cherished garment. Whilst it will never be as good as new, the following treatment will be extremely effective in most cases:

Firstly clean the garment. We suggest using Granger’s G-Wash Cleaner Plus (Be sure to use warm water to wash and rinse).To restore the water repellency to Gore-Tex, use Granger’s Waterproofing for Synthetic Fabrics. 

Place the treated garment in a drier for 45 minutes at medium heat to heat-set the fininsh and remove it promptly. For soft-shell garments, Granger’s offers Soft Shell Proof to restore water-repellency.