This site cites five specific sources worth checking directly rather than assuming what they cover — one NIH Office of Dietary Supplements source per named ingredient.
Biotin and keratin production, Vitamin B12 and cellular function, Vitamin B6 and metabolic function, Folate and cellular renewal, and Pantothenic Acid and skin barrier function — all from the NIH Office of Dietary Supplements.
This site is direct that these citations concern research on the individual nutrients and their general roles, not a clinical trial of the finished Gelagen gummy — worth reading each source as ingredient-level background specifically.