Healthy Aging

A best-selling 1,000 mcg cyanocobalamin tablet at about 5 cents a day; small and easy to swallow, with no third-party seal.

20 g of grass-fed bovine collagen per scoop with a small probiotic dose, NSF Contents Certified and NSF Gluten-Free, at a mid-range price per gram.

20 g of grass-fed bovine collagen peptides per serving and nothing else, NSF Certified for Sport; the TikTok Shop and Amazon bestseller that set the category.

Single-ingredient bovine collagen with a full amino acid profile on the label, NSF Certified Gluten-Free; 11 g scoops make the dose flexible, and it is a TikTok Shop staple.

The budget pick: 20 g of grass-fed bovine collagen per serving for roughly a dollar on Amazon, with a full amino acid profile, though it lacks a named third-party certification.

A '10 types of collagen' blend with vitamin C and a probiotic; heavily marketed, but the collagen sources sit in an undisclosed blend and it costs more per gram.

A USDA Organic fruit-and-vegetable powder sold on an aging study that did not show clear benefits; pleasant flavors, but about $3 a scoop with unquantified blends.