Collagen After 45: What Type I and Type III Peptides Actually Do
Quick answer: After 45, your body produces roughly 1 percent less collagen every year. Type I collagen is the main structural protein in skin, tendons, ligaments, bone, and hair. Type III collagen sits alongside it in skin and blood vessels, providing the elastic quality that lets them stretch and spring back. Hydrolyzed collagen peptides give your body pre-broken-down building blocks that absorb through the gut wall and feed directly into collagen synthesis. An 8-week human trial found that 1000 mg per day of collagen peptides raised a direct marker of Type I collagen synthesis by 165 percent compared to placebo. Below is what each collagen type does in the body, what the research supports, and what a realistic timeline looks like by tissue.
Why collagen production falls after 45
Collagen is the most abundant protein in your body. It accounts for roughly 30 percent of total protein and forms the structural scaffolding that holds skin, joints, bone, and connective tissue in shape.
The fall in collagen production after 45 has two main drivers.
The first is estrogen. Estrogen has long been the signal that tells skin fibroblasts to keep producing collagen at a sustainable rate. As estrogen levels decline through perimenopause and menopause, that signal weakens and collagen output drops. Research suggests women lose up to 30 percent of skin collagen in the first five years after menopause, then about 2 percent per year after that.
The second driver is amino acid availability. Collagen requires specific amino acids to build, particularly glycine, proline, and hydroxyproline. These are conditionally abundant in younger bodies but become harder to maintain at adequate levels from diet alone as you age. Hydrolyzed collagen peptides address this directly by delivering these amino acids in a pre-digested form that crosses the gut wall efficiently.
What Type I collagen does
Type I is the most abundant collagen in the human body. It forms dense, strong fibres in the dermis, the thick inner layer of your skin, where it gives skin its tensile strength and holds the surface structure in place. When Type I collagen production drops, skin thins, lines deepen, and the support framework that keeps it from creasing under gravity begins to loosen.
In tendons and ligaments, Type I collagen forms the tough, load-bearing cables that connect muscle to bone and bone to bone. It is what allows a tendon to bear force and snap back. In bone, it provides the protein matrix that calcium and phosphorus mineralise on top of. Without a healthy Type I collagen scaffold, bone mineral cannot organise properly, which is why collagen loss and bone density loss tend to accelerate together through menopause.
In hair, Type I collagen forms the structural cortex of each strand and provides the protein environment that sustains the hair follicle through its growth cycle. Much of the hair thinning that happens after 50 is partly a loss of the Type I collagen framework around and within the follicle, before any visible change appears at the scalp.
What Type III collagen does
Type III collagen is thinner and more flexible than Type I. It appears most densely in skin alongside Type I, as well as in blood vessels and internal organs. It is what gives skin its elasticity. Where Type I provides the structure, Type III provides the elastic return that lets the structure move.
After menopause, the decline in Type III collagen in the skin wall is part of what drives the laxness that tends to appear first at the jaw and neck. The skin does not spring back after a stretch the way it did at 35. In blood vessels, Type III provides the flexibility that allows arteries to expand with each heartbeat and return to their resting diameter. Reduced Type III production in the vessel wall is one of the structural changes associated with rising arterial stiffness after menopause.
Type III collagen also plays a role in wound repair. It is among the first structural proteins to arrive in a healing wound, forming the preliminary repair scaffold before Type I collagen reinforces it. A cut or bruise that healed cleanly and quickly at 40 may take longer and leave more marking at 55, partly because the Type III repair response is slower.
The human research on collagen peptides
The strongest direct human data on what collagen peptides do to collagen synthesis comes from an 8-week randomized controlled trial by Neltner and colleagues, published in the Journal of Dietary Supplements in 2022.
Thirty-five healthy adults took either 500 mg, 1000 mg, or a placebo daily. The researchers measured Pro-C1a1, a direct blood marker of active Type I collagen synthesis.
At 500 mg per day, Pro-C1a1 rose by 94 percent compared to placebo. At 1000 mg per day, it rose by 165 percent, with serum levels climbing from 42.7 to 113.1 nanograms per millilitre. At the same time, hydroxyproline, a marker of collagen breakdown, fell by 29 percent in the 500 mg group.
The study enrolled men, which is worth noting honestly. The amino acid delivery mechanism is not sex-specific, but the hormonal environment differs. For women going through menopause, the base rate of collagen loss is higher, which means the potential benefit is real but the published numbers come from a different hormonal context. Human trials specifically in postmenopausal women on collagen peptide supplementation are an area where the research field has room to grow.
How shilajit connects to collagen production
There is a second pathway for collagen support that runs from the inside rather than from dietary supply.
In a 2016 trial published in the Journal of Medicinal Food, Das and colleagues gave 500 mg of shilajit daily to 16 participants for 8 weeks and then took muscle biopsies from the participants' leg muscles. They ran gene expression analysis on the tissue samples. Seventeen genes in the collagen and extracellular matrix cluster were significantly upregulated at the end of the trial.
COL3A1, the gene that codes for Type III collagen, was 5.18 times higher. COL1A2, a key structural chain in Type I collagen, was 5.13 times higher. COL1A1 was 4.61 times higher.
These are gene-level changes driven by the fulvic acid and mineral complex in shilajit, not by an external supply of collagen amino acids. The body was producing more collagen instructions. Combined with a collagen peptide supplement that gives it the building material to act on those instructions, both sides of the production chain are addressed.
In a separate 2019 trial in healthy adult women, Das and colleagues found that 14 weeks of shilajit supplementation upregulated genes related to extracellular matrix repair, the structural network your skin and connective tissue depend on. Skin perfusion also improved over the course of the trial.
What a realistic timeline looks like by tissue
Hair and nails tend to respond first. Both depend heavily on Type I collagen frameworks, and both turn over faster than skin or joints. In collagen supplementation trials, hair thickness and nail brittleness improvements appear at the 3 to 4 month mark most consistently.
Skin elasticity and firmness are measured at 8 to 12 weeks in most trials. The changes are real but incremental. This is not an overnight transformation. What you are doing is restoring the supply of raw material so your body can gradually rebuild structure it has been losing for years.
Joints take the longest. Cartilage has almost no direct blood supply, which means repair is slow regardless of the nutrient availability driving it. Joint collagen trials typically run 6 to 12 months, and the meaningful improvements in comfort and mobility appear toward the end of that range. The mechanism is sound but the timeline reflects the biology of cartilage, not any deficiency in the intervention.
What to look for in a collagen product
Hydrolyzed collagen peptides are collagen that has been enzymatically broken down from its original triple-helix structure into short peptide chains small enough to cross the gut wall intact. Intact collagen protein is too large to absorb in meaningful amounts. The hydrolysis step is what makes the difference between a supplement that delivers amino acids to the right place and one that is largely digested away before it gets there.
Grass-fed bovine sourcing matters for two reasons. The research that showed positive results in humans used bovine sourcing. And grass-fed animals carry a lower baseline of synthetic hormone residues in their connective tissue, which is relevant when the raw material comes from that tissue.
A product that contains both Type I and Type III is more complete than one that specifies only Type I. For women over 45 who want to support skin elasticity alongside structural support in hair and joints, both types are relevant.
Optimum's grass-fed hydrolyzed collagen peptides contain both Type I and Type III from bovine sourcing. You can find them here: https://www.liveoptimum.co/products/grass-fed-hydrolyzed-collagen-peptides
References
- Neltner TJ, et al. Collagen peptide supplementation increases serum type-1 procollagen in healthy male adults: a randomized, double-blind, placebo-controlled trial. Journal of Dietary Supplements. 2022. https://pubmed.ncbi.nlm.nih.gov/36546868/
- Das A, et al. The human skeletal muscle transcriptome in response to oral shilajit supplementation. Journal of Medicinal Food. 2016. https://pubmed.ncbi.nlm.nih.gov/27414521/
- Das A, et al. A clinical study to determine the effect of shilajit on gene expression profiling in women. Journal of the American Nutrition Association. 2019. https://pubmed.ncbi.nlm.nih.gov/31161927/
- Schepetkin IA, et al. Fulvic acid increases type II collagen secretion by bovine chondrocytes in vitro. Cell and Tissue Research. 1999. https://pubmed.ncbi.nlm.nih.gov/10398891/