Are your locks looking a little lackluster lately? Maybe your once-thick mane is now noticeably thinner, and it seems no fancy conditioning treatment can resurrect your brittle strands.

The truth is, our hair can tell us a lot about our general health, so if your strands seem to have lost their strength and shine—particularly if you’re not actively damaging your hair with, say, problematic heat styling or chlorine on the regular—it could be your body’s way of letting you know that it needs some TLC. Here are six supplements that can help.

 

1. Multivitamins & Multiminerals

Dr. Daved Rosensweet, founder of I Wonder, Doctor, a website about nutrition and supplements, recommends both a high-quality daily multivitamin to support overall health and a multimineral complex, which will offer up minerals like zinc, copper, selenium, magnesium, and calcium. When used to supplement a well-balanced diet, these can help bridge the gap between any potential nutritional deficiencies.

Inadequate amounts of minerals have been shown to play a key role in hair loss. For example, a lack of zinc and copper both have been associated with hair loss and thinning, according to a study in Annals of Dermatology.

Just take note: If you don’t want to increase your iron intake due to an iron disorder, there are some multiminerals that come without iron.

2. Protein

Next, Rosensweet says it’s a good idea to take stock of whether or not you’re getting enough protein throughout the day. If not, he advises adding protein powder to your daily regimen, as well. After all, our hair is made out of protein and minerals.

So how much protein do you actually need? About 0.8 grams of protein per every kilogram of bodyweight, according to the USDA. So a 130-pound person would need 48 grams of protein per day.

However, that’s just a baseline. If you’re a weightlifter or an endurance athlete—or even if you’re trying to lose weight without losing the muscle you’ve packed on—you’ll need more (somewhere between 1.2 and 3.5 grams of protein per every kilogram of bodyweight). More on that here.

3. Biotin & Collagen

You’ve probably seen dozens of biotin- and collagen-based shampoos, conditioners, and beauty supplements out there—and there’s a good reason for that (besides the two ingredients being super-on-trend these days): Studies suggest that age-related hair loss is associated with a lack of collagen, while research in the International Journal of Trichology found that biotin promotes overall hair health.

4. Vitamin D

People tend to associate vitamin D with bone health, but it may also play a role in our hair’s health. In fact, a study in Dermatology Online suggests that vitamin D is integral in the cycling (or regrowth) of our hair follicles.

Vitamin D is also something plenty of people are short on—especially those living in less sunny environments—so it’s key that you get enough for your overall health.

5. B Vitamins

B vitamins play a key role in promoting hair health. We already know that biotin (B7) is crucial, but so is cobalamin (or B12), the lack of which is connected to excess hair loss in some cases of anemia.

Pantothenic acid (B5) helps to prevent early graying, and boosts the hair’s natural color. But its benefits are more than, well, strand deep: Vitamin B5 also promotes hair growth and regulates the function of sebum glands.

Folate or folic acid (B9) helps support hair health by creating red blood cells and hemoglobin, both of which transport oxygen to hair, helping to promote the growth of new hair follicle cells.

6. Viviscal

Viviscal is an oral marine protein supplement many people use to promote hair health. It features a blend of AminoMar complex, biotin, and zinc.

Related: Shop supplements, topical products, and more.

Other Considerations

If your diet is on point but your hair is still an issue, there could be another culprit: your hormones. Hair loss on the scalp and the body may indicate hormonal issues, like with people who have severe hypothyroidism or other endocrine system disorders.

The endocrine changes that occur after giving birth can result in postpartum hair loss, and may last for as long as 15 months. And for women experiencing menopause, the hair follicles are also affected.

With hormonal hair issues, you might notice thinning hair or strands that fall out in large clumps when you brush it. If you suspect your troublesome tresses might be related to a hormonal imbalance of some kind, consider making an appointment with your doctor.

The Bottom Line

“When someone’s hair is not healthy, there are underlying problems, and very often they’re nutritional,” says Rosensweet. This means that healthy hair begins with healthy nutritional habits.

The very best place to start is with a diet rich in organic (versus non-organic) foods, says Rosensweet—particularly fruit, vegetables, and dairy, which studies, like this one in the British Journal of Nutrition, have shown contain more antioxidants (which protect against oxidative stress that also affects hair) and omega-3 fatty acids (good for your hair, skin, an overall health) than their non-organic counterparts. So, the more nutrients we can get naturally–and organically—from our meals, the better.

Related: I Drank Collagen For 30 Days—Here’s How It Turned Out