Ask an expert: Collagen according to a nutritionist

Confused about collagen? You’re not alone. Despite hearing a lot of hype, many of us are in the dark about what collagen actually does, what happens to our collagen reserves as we age and what collagen supplements do. That’s why we put questions to our in-house nutritionist, Alex Thompson – so you can discover everything from the science of collagen to why marine collagen might be one of the most effective forms around.

"Collagen is known as an ‘elastic structural protein’, which means it provides both strength and flexibility to key parts of your body," says Alex. "For example, collagen keeps your bones strong but with a bit of flex, as brittle bones are more prone to breaking." Another ‘superpower’ of collagen is that it provides the body with amino acids like glycine and proline, which are needed to maintain and repair these tissues. Collagen sends signals between cells, helping them to repair damaged tissues in the body.¹

As well as providing the basis for many different tissues in our body, collagen also helps to form keratin, which Alex describes as: “the major structural protein in your hair. It’s also core to the formation of cartilage, which works as a shock absorber and allows free movement in your joints."²

Collagen loss is a natural part of the ageing process. We lose about 1-1.5% of our collagen every year, from around our mid-20s, according to researchers.³ “For most of our lives, men and women lose it at pretty much the same rate. But then women lose it faster during the first five years after menopause,” says Alex.

According to this nutritionist, they may be a helpful addition. “By taking a collagen supplement, you’ll give your body more of those all-important specific amino acids, glycine and proline. They come with many potential health benefits,” continues Alex. Collagen is found in meat and fish, but the highest levels are found in animal skin, bones and connective tissues. “The majority of us aren’t nibbling on fish bones or connective ligaments very often, so that’s why supplementing might be a good idea.”

“This depends on your main reason for supplementing,” says Alex, referencing goals such as plumper skin and post-exercise recovery. “While adequate intake is important, more isn’t necessarily better – benefits from collagen tend to depend on consistent use over time rather than higher doses,” says Alex, who also talks about the importance of taking it for the recommended duration (more on this later). “Once you go over 25g a day, you’ve saturated the benefits.”

Bovine collagen is made from cow bones and hides, while marine collagen comes from fish skin and scales – and both can be beneficial. “If you have dietary restrictions like an allergy, you’re pescatarian or you have religious or cultural exclusions, this might swing it for you,” says Alex. Most marine collagens are Halal but always check that the product has official Halal certification.

“This depends on your particular focus and the amount of collagen you’re looking for. Gummies generally have less collagen per serving compared to powders. They also tend to be more expensive gram for gram.” But the choice is really down to what you prefer and will fit in with your daily habits, so that you take it consistently.

“Based on a small study, to see a difference in your skin elasticity and hydration levels, you’ll want to take collagen supplements of up to 10g a day for at least eight weeks,” says Alex. “To see the post-exercise recovery benefits, researchers¹⁰ found that taking a high intake of 15-20g of collagen per day for just one week can have an effect. Or, like the study suggests, try 5g per day, and you could feel a difference within eight weeks, too.” For many of us, that means it's worth a try.

Yes, the sun does damage your collagen but not by simply stopping it from being produced. Research shows that long-term sun exposure alters the structure of collagen in your skin – turning what should be smooth, organised fibres into irregular, damaged ones.¹¹ Although your skin continues to make collagen, it’s broken down and rebuilt in a disorganised way and some of it is replaced with abnormal elastic material. ¹¹ This means the overall quality of collagen declines, which weakens the skin and contributes to wrinkles and loss of firmness over time.¹¹

Whether you prefer collagen in your morning coffee, post-workout shake or evening routine, the key is finding a way to make it part of your everyday habits. Pair it with a balanced diet, support it with nutrients like vitamin C and give it time – because real results come from what you do consistently, not occasionally. Think of collagen as a long-term investment in your skin, joints and overall wellbeing. Hungry for some tasty ways to support your skin? Good news, sink your teeth into our skin-loving rocky road beauty roll or sip your way through this tropical beauty-boosting smoothie with vitamin C.

Disclaimer – This article provides informational advice and is not a substitute for medical care. Curated by experts for accuracy, we take great care to ensure the information is up-to-date and relevant. However, you should always consult your GP or healthcare professional before using supplements or alternative products, particularly if you have medical conditions or are under supervision.