Collagen: Timing, Types, and the Science Behind It
Beauty & Skin · approx. 8 min. reading time
From the mid-20s, the body slowly reduces its own collagen production – by approximately one percent per year, with a significant jump around menopause. Collagen is the structural protein that gives skin, tendons, cartilage, and connective tissue their firmness. It's no wonder that collagen powders and capsules are among the best-selling supplements. But are you even taking it correctly? And what really makes a difference?
What happens in the body when you take it
Collagen as a large protein cannot simply be "integrated" into the body as it is. Therefore, hydrolyzed collagen is used: broken down into small, highly soluble peptides that are absorbed through the intestines. These peptides provide building blocks (especially glycine, proline, hydroxyproline) and also apparently act as a signal to the skin cells to produce more collagen and hyaluronic acid. For this to work, however, the body needs something crucial: vitamin C. It is the cofactor that enzymes need to assemble the collagen structure in the first place – without sufficient vitamin C, even a lot of ingested collagen remains ineffective. This is one of the reasons why good formulations contain both together.
Why collagen type and peptide size make a difference
Not every collagen supplement is structured the same way – two details are worth a closer look:
Type I and III instead of just Type I. In the body, collagen occurs in different types, which have different functions. Type I is by far the most common – the firm, tensile structural protein in skin, bones, and tendons. Type III occurs in the skin together with Type I and is closely linked to its elasticity and suppleness; its proportion relative to Type I tends to decrease with age. Some collagen sources – such as marine collagen derived from fish scales – provide almost exclusively Type I. Collagen from bovine hide (bovine collagen), on the other hand, naturally contains Type I and III together, in a ratio that more closely resembles the body's own composition in the skin.
Peptide size determines absorption. Collagen is broken down into fragments of different sizes through hydrolysis. The smaller these peptides are, the more easily they can be absorbed through special transport pathways in the intestinal mucosa – sometimes even as intact short peptide chains, as studies on the absorption of collagen fragments into the blood show. A fine collagen powder, consistently hydrolyzed down to very small fragments, is therefore not just a marketing term but has a comprehensible reason: better solubility and easier absorption.
Regarding origin: Pasture-raised (grass-fed) is primarily a matter of animal welfare and transparency – for the amino acid structure of the collagen derived from it, it does not make a proven difference in effect. For those who value origin and animal husbandry, it is still a relevant selection criterion.
Timing: When to best take collagen
Most studies on oral collagen involve daily intake over at least 8–12 weeks – the time of day itself plays a smaller role than consistency. However, two times have proven effective in practice:
- In the morning on an empty stomach, so that the amino acids are absorbed undisturbed by other proteins from the meal.
- In the evening, shortly before bedtime – the body's own collagen and skin cell regeneration primarily occurs at night while you sleep.
Neither of these is proven as "exclusively correct" by studies, but both variants fit well with the skin's natural rhythm.
How to best take it
- As a powder: dissolves residue-free in both cold and warm drinks – in coffee, tea, or a glass of water, as preferred. The peptides are not damaged in the process.
- As a capsule: simply take with a large glass of water, without timing around meals playing a major role.
- Combine with water instead of a lot of milk if larger amounts of calcium are consumed at the same time – but dairy products are not a problem if they are not the only liquid for intake.
- Add a source of vitamin C, if your collagen product does not contain any: A glass of orange juice, a kiwi, or a handful of berries with your collagen serving are sufficient, as vitamin C is water-soluble and is continuously used throughout the day.
What additionally supports intake
Collagen formation is not a solo process – a few habits make a measurable difference:
- Sun protection. UV radiation is one of the best-documented accelerators of collagen breakdown. The best dietary supplement does little if unprotected sun exposure works against it daily.
- Sufficient protein overall. Collagen peptides are a supplement, not a substitute for an overall protein-rich diet.
- Do not smoke. Cigarette smoke activates enzymes that specifically break down collagen – one of the clearest documented correlations in skin aging research.
- Sleep. Growth hormone release and cell repair, including in the skin, largely occur during deep sleep phases.
Not just for the skin: tendons, ligaments, and joints
Collagen is often reduced to its effect on skin appearance – yet it makes up an even larger proportion in tendons, ligaments, and joint cartilage. Precisely these tissues are subjected to the greatest mechanical stress during regular exercise, especially during running, jumping, or strength training. A widely noted study in the American Journal of Clinical Nutrition had participants consume vitamin C-enriched gelatin preparation (a collagen source) about an hour before short, intense training and subsequently measured increased collagen synthesis in the blood (AJCN, Shaw et al.). The timing "before exercise, with vitamin C" was not accidental, but follows the same logic as for skin collagen: No collagen synthesis without vitamin C, regardless of the tissue. For active people, collagen is therefore not just a beauty topic, but a connective tissue topic.
For women after menopause
The decline of estrogen during menopause measurably accelerates collagen loss in connective tissue – reviews of skin physiology describe a significant decrease in skin collagen especially in the first years after menopause, parallel to falling estrogen levels (Dermatology and Therapy, Review). This affects not only the skin, but the same connective tissue metabolism that also affects joints and bones. Therefore, collagen in this phase of life is increasingly discussed not as "anti-aging cosmetics," but as part of a more comprehensive strategy for connective tissue and mobility – alongside strength training, adequate protein, and vitamin D, which also play a role in this context.
What you can realistically expect
Several independent study reviews in recent years find a measurable effect on skin moisture and elasticity with regular intake over several weeks – usually noticeable from the sixth to eighth week, not after three days. Those who expect immediate, dramatic changes will be disappointed; those who stick to it as a daily routine for one to two months have the most realistic chance of noticing a difference.
Good to know
Collagen peptides are very well tolerated, even over long periods. Anyone currently suffering from a fish allergy should check the source of the collagen (fish, bovine, or plant-based alternatives differ here).
Relevant to this
medi Collagen is available both as a powder – with finely hydrolyzed collagen peptides of type I and III from pasture-raised cattle, plus hyaluronic acid, vitamin C, zinc, and biotin – and as capsules (additionally with copper in the formulation), depending on what suits your daily routine better.
Sources
- Systematic review & meta-analysis on collagen supplements and skin hydration/elasticity, Indian Journal of Dermatology, Venereology and Leprology. ijdvl.com
- Effects of Oral Collagen for Skin Anti-Aging: Systematic Review & Meta-Analysis, Nutrients 15(9):2080 (2023). mdpi.com
- Effects of Collagen Supplements on Skin Aging: Systematic Review & Meta-Analysis of RCTs, The American Journal of Medicine (2025). amjmed.com
- Vitamin C-enriched gelatin supplementation before intermittent activity augments collagen synthesis, The American Journal of Clinical Nutrition. ajcn.nutrition.org
- Estrogen and skin aging, Review, Dermatology and Therapy. link.springer.com
- Iwai, K. et al. Identification of Food-Derived Collagen Peptides in Human Blood after Oral Ingestion of Gelatin Hydrolysates, Journal of Agricultural and Food Chemistry (2005). PubMed 16076145
This article is for general information purposes only and does not replace individual medical advice.
