I work at the YMCA and teach yoga, so am in activewear most days of the week. These merino thongs are finally the perfect combo of comfort (can't feel them on!), no panty lines, and NO ODOR even after teaching a class or sneaking in a work out. I ordered the three-pack and immediately ordered another so I have plenty for every day of the week. So happy! I would say they run a tad large, I am always a medium and ordered a medium, these are a tiny bit on the looser side but I didn't want them tight, plus I know merino can shrink, so I kept them and am very happy. For reference I am 5'7" and 150 lb.