Thorne Collagen Fit Review

Collagen peptides, the main ingredient, come at 15 grams a day, the same amount used in several training trials. A review of 19 trials found small gains in fat-free mass, muscle structure and maximal strength in adults who trained for at least 8 weeks, though certainty was low to moderate ^[1]. In 12-week training trials, 15 grams daily added more fat-free mass than placebo in middle-aged men ^[2], women ^[3] and older men with muscle loss, who also gained leg strength ^[4]. Ten grams daily added a little more muscle than placebo in trained men ^[5]. However, in older adults who did not train, a year of collagen did not change muscle size or strength ^[6]. Nicotinamide riboside is present at 125 milligrams, well below the 1,000 milligrams used in some trials, and pooled trials found no benefit for muscle mass or function ^[7][8]. Betaine is only a trace amount, 50 milligrams versus the 2.5 grams studied, and even at full dose most trials found no gain in strength or power ^[9][10]. Animal and cell studies are never counted.

Collagen is the main ingredient, and most of the panel recommends or uses it: three recommend it, five take it, one is neutral, and one has stopped. People take it for joints, tendons, skin, and muscle, and several mention gut and sleep. Doses cluster around 10 grams a day, with a few taking 15 grams about an hour before exercise, sometimes with vitamin C, while another suggests 2.5 to 5 grams a day of hydrolyzed peptides for at least 8 weeks for skin. Cautions come from two panelists who say collagen is a poor, incomplete protein for building muscle compared with other proteins and should not be the only protein source, and from one who says it will not repair a damaged gut wall. Nicotinamide riboside is a smaller ingredient in this product, and the panel is mixed on it, with one recommending it, one skeptical and no longer using it, and others calling the evidence limited.