Yes -- with meaningful clinical evidence. The concern that oral collagen is 'just digested into amino acids' understates the research. Hydrolyzed collagen peptides (low-molecular-weight, specifically processed) survive gastric digestion as di- and tripeptides, are absorbed intact, and accumulate in skin tissue. The Proksch et al. series (2.5 g/day, 8 weeks): 20% improvement in skin elasticity. Borumand et al. (2015): 65% increase in pro-collagen type I at 12 weeks. The mechanism is now well-characterized: collagen peptide receptor signaling on fibroblasts stimulates endogenous collagen synthesis.*

The forms with the strongest evidence for skin: hydrolyzed marine collagen (Type I, highest glycine/proline content) and hydrolyzed bovine collagen (Types I and III). 'Hydrolyzed' is essential -- it means the collagen has been processed into low-molecular-weight peptides (under 5,000 Da) that absorb intact. Non-hydrolyzed collagen protein or gelatin does not have the same clinical evidence for fibroblast stimulation. Dose: the clinical research has been done at 2.5--10 g/day -- most collagen supplements providing under 2 g/serving are below the studied range.*

Vitamin C is not optional for collagen synthesis -- it is biochemically required. The enzymes that create collagen's triple-helix structure (prolyl-4-hydroxylase and lysyl hydroxylase) require Vitamin C as a cofactor electron donor. Without it, procollagen cannot be properly hydroxylated, and the resulting collagen is structurally unstable. This is why scurvy (Vitamin C deficiency) produces tissue breakdown -- the collagen maintenance system fails. Taking collagen peptides without adequate Vitamin C is like adding building materials without the construction tools to assemble them.*

The clinical trial timelines: elasticity improvements are detectable at 8 weeks; wrinkle depth reductions require 12 weeks; skin moisture improvements from hyaluronic acid start around 6--8 weeks. Collagen remodeling is slow biology -- the dermis is not a rapidly turning over tissue. Most people notice skin hydration improvements before structural changes (firmness, wrinkle depth). A minimum 12-week commitment is necessary to evaluate the skin benefits of a collagen protocol.*

There is no vegan collagen -- collagen is an animal-derived protein. 'Vegan collagen boosters' are products containing the amino acid precursors (glycine, proline, Vitamin C) and cofactors (zinc, silica) that the body uses to synthesize its own collagen. They support endogenous collagen production rather than directly stimulating fibroblast synthesis the way collagen peptide receptor signaling does. For vegans, the collagen support stack (high-dose Vitamin C, L-Lysine, L-Proline, Zinc, Silica) is the evidence-informed approach to skin aging support.*

Biotin has strong evidence for hair and nail conditions caused by biotin deficiency -- and some clinical support for non-deficient adults with brittle nails specifically. The 2015 Scheinfeld et al. review found biotin at 2.5--5 mg/day produced improved nail thickness in brittle nail syndrome. For hair, the research is less definitive: documented biotin deficiency produces hair loss that responds to repletion; hair loss without biotin deficiency is multifactorial. Biotin is water-soluble and safe at high doses, making it low-risk to trial in cases of hair thinning.*