You can get supplements for just about anything these days. Feeling bloated? There are supplements for that (whether they work or not is another matter). Want to feel happier? Try taking 5-HTP. Looking to boost your libido? Goop’s DTF pills will (apparently) sort you right out.

Among the most popular are hair, skin and nail supplements, which promise stronger, longer talons and manes with vitamin E-rich formulas and buckets of collagen. Who wouldn’t want a tablet or gel that targets those very visual signifiers of health? Certain nutritional deficiencies metabolise in brittle hair (biotin), flaking nails (iron) and dull skin (vitamin D), so there’s definitely logic behind taking supplements to combat those symptoms. 

The issue, however, is that we can’t choose where nutrients go in our body. If you live with gut symptoms, for example, you might be tempted to supplement collagen because collagen can help to repair the gut wall. But registered nutritionist Marjolein Dutry van Haeften explains that collagen is the kind of nutrient your body can’t get enough of – and as a result, it prioritises where it’s needed first before using it to repair less important areas. 

“It can really help the gut, but it might need to go to joints or other connective tissues. You don’t absorb collagen – it just gets broken down into amino acids, and then your body does with it what it will.”

That’s not to say that supplements don’t work, but they might not do exactly what you think. You can reduce your body’s capacity to absorb supplements, for example, by drinking coffee with your iron supplement, but vitamins and minerals themselves aren’t going to stop or start working.

The issue is that many supplements are marketed for specific reasons. On my desk right now, I’ve got packets of pills that promise better periods, increased energy, clearer mind and better skin from large ingredients lists. Perhaps they can do all of those things, but if I’m already a little low on any of the nutrients, my body’s going to take that and use it for whatever it needs – rather than the purpose listed on the packet. If a collagen supplement goes to strengthening your bones rather than your skin, that’s not a bad thing – clearly, your bones need that little extra support. 

It’s worth saying that van Haeften does believe that some nutrient combinations make sense for particular processes. If you’re looking to think clearer, you might be after a cognitive combination that includes B vitamins and ginkgo (which increases cerebral blood flow).

“Companies will have picked things that work together to support a particular function in the body,” she explains.

But when it comes to hair, skin and nail supplements, van Haeften believes they’re “basically a multivitamin”. And that might make all the difference if you don’t already eat a very nutrient-rich diet or need a little nutritional support – but they might not automatically set to work growing your locks.

For more supplement support, visit the Strong Women Training Club.

Images: Getty