Can collagen drinks really make a difference to your skin? Dr Haran Sivapalan takes a look at the research behind these expensive little shots.

In Greek mythology, Eos, the goddess of dawn, asked Zeus to give her lover Tithonus the gift of immortality. Somewhat forgetfully, she neglected to request that her lover also receive the gift of eternal youth. Over time, Tithonus continued to live, but his muscles became weaker, his skin grew wrinkled and less supple; it began to sag. Despite immortality, Tithonus’ body and its largest organ, the skin, continued to undergo the process of aging.

Skin aging is a complex process involving a wide range of structural, hormonal and genetic changes. Depending on the cause of these changes, we can distinguish between two types of aging: extrinsic and intrinsic. Extrinsic aging refers to the changes that result from exposure to things outside of the body, such as UV radiation from the sunlight or toxins from tobacco smoke. By contrast, intrinsic aging refers to the body’s internal changes that happen with the passage of time. Intrinsic aging is largely determined by your genes.

As a result of both intrinsic and extrinsic aging processes, aged skin becomes like that of Tithonus: less firm and wrinkled. Aged skin has a thinner epidermis (the outer layer of skin), less elasticity and, along with other key molecules, a decreased content of collagen – an important structural protein.

Given this loss of collagen in the skin during aging, and the fact that collagen’s in topically applied creams are generally too large to penetrate the skin’s outer layer, it seems plausible, at least intuitively, that replenishing the levels of collagen through oral supplements – ready made drinks or powders you mix to make a collagen drink  – could counteract the aging process. Of course, intuitions are not necessarily born out by empirical scientific studies. So, what does the science say?

Oral collagen supplements

Once in the digestive system, collagen gets broken down into smaller collagen peptides. Despite much controversy over where these peptides go to next, studies using radioactive compounds to track their movement  have indeed shown that collagen peptides can eventually end up in the skin. But, does orally administered collagen go on to improve the skin once it’s there?

Let’s take a look.

Clinical trials of a 10g oral collagen supplement

In 2015, clinical trials studied the effect of a 10g oral supplement containing collagen peptides derived from either fish or pig cartilage. The trials reported significant improvements in skin moisture and collagen density. After 12 weeks, collagen density in the dermis was shown to increase by 9%.

The studies, published in the Journal of Cosmetic Dermatology, also investigated the effect of the 10g supplement on the degradation of collagen in the skin, a process that occurs in aging. Using a technique called “reflectance confocal microscopy”, researchers were able to look at collagen fibres in the skin using a microscope and assess whether or not they were fragmented. They found that the collagen supplement significantly reduced collagen fragmentation in the dermis over 12 weeks. This result, the authors suggest, demonstrates the product’s anti-aging potential.

There are, however, some limitations to the these studies. The trial investigating the effect on skin moisture only had 33 people – a fairly small sample size.  It is also worth bearing in mind that the above studies were conducted by the very same company that manufactures the supplement.

Open-label study of a 50ml collagen drink

In a similar fashion, another leading manufacturer has published studies on its own product: a 50 ml nutritional drink that contains 5g collagen, hyaluronic acid and other vitamins and minerals. One study, published in the journal Clinical Interventions in Aging, looked at the effect of taking the drink over 60 days. Dermatologists observed the skin the 217 subjects and reported fewer wrinkles, less dryness and a reduction in the depth of nasolabial folds (skin folds that extend from the sides of the nose to the corners of the mouth). A smaller group of subjects also had their skin tested with ultrasound equipment, in order to assess the density of collagen in the dermis. The authors reported a 12-19% increase in collagen density after 12 weeks.

Although it had a large number of subjects, this study was what clinicians call an “open-label” study. This means that there was no placebo control group and it was “unblinded” – researchers (and subjects) knew which individuals were taking the supplement. A lack of blinding increases the risk of the researchers unwittingly biasing the results. Furthermore, the lack of placebo control group makes it difficult to pinpoint any of the reported benefits specifically onto the collagen supplement. Clearly, a large, double-blinded randomised controlled trial is required to more thoroughly assess the benefits of the collagen-containing drink. .

Clinical trial of 2.5g and 5g collagen supplement

In contrast to the previously mentioned study, Proksch and colleagues did manage to conduct a double-blinded, placebo-controlled study of a commercially available collagen supplement. For 8 weeks, subjects were given either a placebo or a supplement containing either 2.5 or 5g of collagen peptides. Skin elasticity was measured by technique that involves applying a suction cylinder to the skin. The vacuum causes the skin to stretch. When the vacuum is stopped, more elastic skin (with a higher content of collagen) will return to its original position more readily.

Compared to the placebo group, those taking the supplement (at either the 2.5g or 5g dose) showed a significant increase in skin elasticity after 8 weeks. This improvement in skin elasticity was also sustained for 4 weeks after subjects stopped taking the supplement. There were no reported differences between the dosage groups i.e. the benefits were the same regardless of whether a person was taking the 2g or 5g collagen supplement. Despite these improvements in skin elasticity, the supplement failed to improve measures of skin hydration and roughness of skin.

Open-label study of a 1g collagen supplement

In small study conducted over 12 weeks, 26 women took a daily 1g collagen peptide supplement derived from chicken cartilage. By the end, their skin boasted significantly fewer wrinkles, less dryness and reduced scaling. There was also a significant increase in collagen content after 6 weeks of taking the supplement.

Unsurprisingly, the small sample size makes this a fairly low quality study. Augmenting this, it was another “open label” study without blinding and a controlled group.

Take home message

So, what can we conclude from these scientific studies? Would the aging Tithonus have benefitted from taking oral collagen supplements? Put simply, the evidence that such supplements can rejuvenate the skin is mixed. While demonstrating positive results, existing studies have been let down by either small sample sizes or an inadequate control group. As is often the case in medicine, more research is required.

This is not to say that collagen supplements do not show promise. Studies do suggest that, in stark contrast to collagen-containing creams, oral supplements may be a viable way of getting collagen into your body. Of course, so is eating a healthy and balanced diet. Similarly, using adequate sun protection and avoiding smoking will respectively protect against the degradation of collagen that follows exposure to UV light and toxins (extrinsic aging). For further advice on keeping the skin healthy, it is best to consult your GP or dermatologist.