Colostrum powder is being studied due to the presence of growth factors and immune substances that may support recovery and muscle building. An early study showed that colostrum supplementation, combined with strength training, could lead to a small increase in muscle mass compared to whey protein (Antonio et al., 2001).
Other controlled studies, however, found no clear benefits compared to whey in terms of body composition or fat loss, for example in elite athletes (Hofman et al., 2002) and older adults (Duff et al., 2014).
Recent reviews confirm that the results are inconsistent: sometimes a small benefit in lean mass is found, but convincing evidence for fat loss is lacking (Jakubowska-Pietkiewicz et al., 2021 – Review). Most experts therefore conclude that colostrum is not a proven "weight loss supplement," but at best a possible addition within a training program aimed at muscle maintenance or growth.