No juice grows hair, and the reason is simple: hair is roughly 90 per cent keratin, a protein, and juice contains almost none. Nutrition does affect hair, but mainly in one direction. Correcting a genuine deficiency in iron, zinc, vitamin D, protein or overall calories can improve shedding. Adding more of a nutrient you already have enough of does nothing, and with vitamin A and selenium, taking too much causes hair loss rather than preventing it.

Last updated: August 2026

What is hair made of, and can a drink supply it?

Hair is a fibre of keratin, a tough structural protein rich in the sulphur-containing amino acid cysteine. Building it needs a steady supply of dietary amino acids, plus the minerals and vitamins the follicle uses to assemble them. A glass of juice contains close to zero protein, so on the single most important input it contributes nothing.

The follicle is also one of the most metabolically demanding structures in the body, dividing faster than almost any other tissue. That is exactly why it is an early casualty when overall intake drops. When the body has to prioritise, hair is near the bottom of the list, well below the heart, brain and immune system.

This is why the most common nutrition-related hair complaint has nothing to do with a missing vitamin. It is undereating. Crash diets, restrictive eating and rapid weight loss push a large share of follicles into their resting phase at once, producing diffuse shedding roughly two to three months later. That pattern is called telogen effluvium, and we have covered it in detail in what causes telogen effluvium.

Which nutrient deficiencies genuinely affect hair?

A short list has real evidence behind it, and each one is confirmed by a blood test rather than by symptoms. The table separates what is worth checking from what gets marketed.

The pattern is worth stating clearly, because supplement marketing depends on blurring it: correcting a deficiency helps, and topping up when you are already replete does not. Our full breakdown sits in essential vitamins and minerals for healthy hair growth, and the B12 picture specifically in vitamin B12 deficiency and hair loss.

Can a juice actually deliver any of these nutrients?

Partly, and not the ones that matter most. Juice is a good source of vitamin C, folate, potassium and a range of polyphenols. It is a poor source of iron, a weak source of zinc, and contains essentially no protein, vitamin D or B12. On the nutrients most often linked to shedding, it barely registers.

The spinach question deserves its own answer, because green juice is sold almost entirely on it. Spinach contains non-haem iron, which the body absorbs far less efficiently than the haem iron in meat and fish, and spinach's own oxalates bind iron and reduce absorption further. Vitamin C in the same drink genuinely improves non-haem absorption, so citrus in a green juice is doing real work. Tea and coffee do the opposite, so keep them to a different hour.

What juice does offer is a painless way to eat more plants, and vitamin C is not nothing: it is required for collagen synthesis and it helps you absorb the iron in the rest of your meal. Just do not mistake it for a treatment. If you are shedding and tired, the useful next step is a ferritin test, not another green juice.

What would a genuinely hair-supportive drink look like?

A blended smoothie built on a protein base, not a juice. Blending keeps the fibre, and the protein base supplies the amino acids that keratin is actually made from. The framework below is more useful than any recipe, because it lets you build it from whatever you have.

1. Start with protein. Greek yoghurt, kefir, milk, soya milk or a plain protein powder. Aim for something in the region of 15 to 20g in the glass, because this is the part that matters most.
2. Add greens plus a vitamin C source. A handful of spinach or kale with berries, kiwi or citrus. The vitamin C improves the absorption of the plant iron alongside it.
3. Add seeds for minerals. A spoon of pumpkin seeds, hemp or ground flaxseed contributes zinc, magnesium and some protein.
4. Add a little fat. Nut butter, avocado or the fat already in dairy. Vitamins A, D, E and K need fat to be absorbed at all.
5. Keep the fruit modest. Half a banana or a handful of berries is plenty. This is a meal component, not a dessert.
6. Treat it as breakfast, not an extra. A drink you add on top of your usual meals is additional calories rather than better nutrition.

That drink is a reasonable breakfast. It is still not a hair treatment, and it will do nothing at all if your hair loss is genetic or autoimmune.

How long before a diet change shows up in your hair?

Three to six months, at minimum. Scalp hair grows roughly 1cm a month, and the follicles that were pushed into their resting phase by a nutritional shortfall take around three months to shed and then several more to visibly regrow. Nothing you eat or drink shows up in a fortnight.

Understanding the cycle helps set expectations. Each follicle spends two to seven years in the active growing phase, a short transitional phase, and then around three months resting before the hair falls and a new one starts. Because your follicles are not synchronised, you normally lose 50 to 100 hairs a day without noticing. A shock synchronises a large group of them, which is why shedding after illness, surgery or a crash diet arrives suddenly and months late.

What can diet not fix?

The two most common causes of hair loss are not nutritional, and no drink, supplement or shampoo changes them. Being clear about this saves people a great deal of money and a great deal of time.

• Androgenetic alopecia, or pattern hair loss. Follicles that are genetically sensitive to dihydrotestosterone gradually miniaturise. It is inherited sensitivity at normal hormone levels, not a deficiency, and it has licensed medical treatments worth discussing with a clinician.
• Alopecia areata. An autoimmune condition producing discrete patches of loss. It needs a proper diagnosis, and some cases respond well to treatment.
• Scarring alopecias. Follicles are permanently destroyed, so early diagnosis is what protects the remaining hair. This is urgent rather than optional.
• Thyroid disease, PCOS and other medical causes. These are treated by addressing the condition, not the hair.

Where does what you put on your hair fit in?

Topical products work on the fibre and the scalp, not on the follicle's biology, and that distinction is where most marketing goes wrong. A shampoo cannot change genetic sensitivity to DHT and cannot correct a deficiency. What it can do is reduce the breakage that makes thinning look worse than it is, and keep the scalp comfortable enough that you leave your hair alone.

That is a smaller claim than the category usually makes, and it is the honest one. Hair that snaps mid-length reads as thinning even when the follicle count is unchanged, so reducing breakage is a genuine visible win, separate from anything happening at the root.

Grow Me® Hair Growth Shampoo, £14.95

A sulfate-free daily shampoo formulated with biotin, caffeine, rosemary, niacinamide and hydrolysed lupine protein, designed to reduce breakage for fuller-looking hair. It is a cosmetic product: it does not treat pattern hair loss, alopecia areata or any deficiency, and it will not do the job that food does. Results vary, and consistent use over 8 to 12 weeks is the fair way to judge it. Pair it with the diet advice above rather than instead of it.

Shop Grow Me Shampoo

On the internal side, if your diet has genuine gaps our sugar-free GrowPro Hair, Skin & Nails Gummies supply biotin, zinc, selenium and B vitamins that contribute to the maintenance of normal hair. Note the selenium warning above and do not stack multiple supplements containing it. Collagen is the other supplement people ask about, and we assessed the evidence in do collagen supplements work for skin and hair.

Frequently asked questions

Which juice is best for hair growth?

None of them grow hair. Hair is built from protein, and juice contains almost none. If you want a drink that genuinely supports hair, blend a smoothie on a yoghurt, milk or protein powder base with greens, seeds and a vitamin C source rather than juicing.

Does drinking green juice help hair loss?

Only if it corrects a real deficiency, which is unlikely. Green juice supplies vitamin C and folate but very little absorbable iron and no protein. If you are shedding, ask your GP for a ferritin test and full blood count rather than increasing your juice intake.

Which vitamin deficiency causes hair loss most often?

Low iron stores, measured as ferritin, is the deficiency most consistently linked to diffuse shedding, particularly in women with heavy periods. Protein and calorie shortfall is arguably more common still, and vitamin D is frequently low in the UK during autumn and winter.

Does biotin actually work for hair?

Only if you are deficient, which is rare in people eating normally. There is no good evidence that extra biotin helps hair in people with adequate levels, and high doses can distort thyroid and cardiac blood test results, so tell your clinician if you take it.

Can too many vitamins cause hair loss?

Yes. Excess vitamin A is a recognised cause of hair loss, and selenium has an unusually narrow margin between adequate and toxic, with hair loss a classic sign of excess. Taking several supplements at once makes accidental overlap easy.

How long does it take for diet to affect hair?

Three to six months at minimum. Hair grows around 1cm a month, and follicles pushed into their resting phase take about three months to shed before regrowth becomes visible. Photograph your parting monthly rather than judging by memory.

Is spinach good for hair?

It is a decent food, but a weak iron source. Spinach contains non-haem iron, absorbed far less efficiently than the iron in meat and fish, and its oxalates bind iron further. Pairing it with a vitamin C source improves absorption, and keeping tea and coffee to another hour helps.

Can nutrition reverse pattern hair loss?

No. Androgenetic alopecia is inherited follicle sensitivity to dihydrotestosterone at normal hormone levels, not a deficiency, so no food, drink or supplement changes it. It does have licensed medical treatments, which are worth discussing with a GP or dermatologist.

The short version

Juice is a pleasant drink and a poor hair strategy. Eat enough protein and enough total food, get ferritin, thyroid function and vitamin D checked if you are shedding, and be wary of vitamin A and selenium rather than chasing more of them. If you want a drink that helps, blend one on a protein base instead of juicing it. Then give any change three to six months, with monthly photos, before deciding whether it worked.

For the topical half of the job, Grow Me sulfate-free shampoo is formulated to reduce breakage for fuller-looking hair. If you would like the wider context on juicing itself, see is juicing healthy. Watermans is a founder-led British brand that has sold more than 5 million bottles since 2012, vegan and made in the UK.