Does zinc help with hair growth?

Only where zinc is genuinely missing, and for ordinary hair loss nobody has tested it properly. We found no randomized trial of zinc on its own for any kind of hair loss. In children with acrodermatitis enteropathica, a rare inherited zinc disorder where hair loss is a hallmark sign, 159 of 174 treated with zinc (91.4 percent) responded, in a review of published case reports. For everyone else the evidence is a link in observational data: across 10 studies with 878 people, those with alopecia areata, the patchy autoimmune kind, had lower blood zinc than healthy controls.

Unsettled. Low blood zinc and patchy hair loss travel together. Whether a zinc tablet regrows hair in someone who is not deficient is a question no placebo-controlled trial has answered. The one zinc-only treatment study we found had 15 patients and no control group, and its result did not reach statistical significance.

What the trials found

Supplement trials where zinc cannot be separated

A 2026 meta-analysis pooled 14 studies in 967 adults with thinning hair who took branded hair supplements such as Nutrafol and Viviscal. The supplements raised anagen hair density, the count of hairs in the growing phase, by 10.48 units against placebo (95% CI 8.81 to 12.14). Every product was a blend of many ingredients, so none of that effect can be credited to zinc. The pooled studies also included open-label and proof-of-concept designs.

The newest synthesis of randomized trials in androgenetic alopecia, the common pattern kind, is a 2025 network meta-analysis of 19 trials in 1658 patients. It compared 16 supplements, and zinc alone was not one of them. We checked the full text for it.

A 2023 systematic review in JAMA Dermatology covered 30 studies of supplements in people without a known deficiency, 17 of them randomized. It named zinc among interventions with potential benefit. It did not pool the results, and the abstract does not say which zinc study it rated or how it was designed, so this is a mention rather than a measured effect.

The one zinc-only study

Fifteen patients with alopecia areata for at least 6 months and low blood zinc took 50 mg of zinc gluconate a day for 12 weeks. Nine of them (66.7 percent) had regrowth, which the authors report was not statistically significant. There was no placebo group to compare with. The dose is above the adult upper limit described below.

When the cause is a real zinc deficiency

The NIH lists alopecia among the signs of zinc deficiency that become more common in older children, alongside delayed growth and frequent infections. In the inherited form, acrodermatitis enteropathica, the case-report review above found zinc worked in most treated children, most often at 1 to 3 mg per kg of body weight a day. It was often ineffective when the disorder came from another metabolic disease. These are case reports, the weakest kind of evidence about treatment, in a condition most readers will never have.

The link, in observational data

The 2025 meta-analysis behind the alopecia areata figure found a standardized difference in blood zinc of -0.69 against healthy controls (95% CI -0.99 to -0.39), with high variation between studies. An earlier 2017 meta-analysis of 10 articles with 764 people found the same for zinc and selenium, and no difference in copper, iron or ferritin. The authors called low zinc a risk factor. Their design can show only that the two go together.

In a case-control study of 100 people in Karachi, those with chronic telogen effluvium, long-running diffuse shedding, had lower zinc in blood and in hair than matched controls. The abstract gives only a p-value, no levels.

After bariatric surgery, 18 studies with 2538 patients found hair loss in 57 percent. It went with lower blood zinc, a standardized difference of -1.13 whose confidence interval runs from -2.27 to 0.01 and so just reaches zero. Low folate and low ferritin were tied to it too. A separate review of gastric bypass patients concluded that routine zinc testing is unnecessary for people without symptoms, and advised testing zinc when symptoms such as hair loss appear.

Myth. Low zinc is not a general cause of pattern hair loss in women. In 289 women with female pattern hair loss, blood zinc was lower in the more severe cases, and that difference disappeared once the groups were matched for age and how long the hair loss had lasted.

Who should be careful

Zinc tablets have a measured cost, even though the trials that measured it were not about hair. A 2024 Cochrane review found zinc taken for colds probably raises non-serious side effects by about a third (risk ratio 1.34, 95% CI 1.15 to 1.55, 16 trials, 2084 people). No treatment trial in that review reported on serious side effects.

Not for everyone. Children can be sick on zinc. In 38 randomized trials in children under 10 with diarrhea, zinc raised the risk of vomiting by 46 percent against placebo, and low doses caused fewer vomiting episodes than high doses. The NIH sets the upper limit at 40 mg a day for adults and 4 to 34 mg for infants, children and teenagers, depending on age. It warns that 50 mg or more for weeks can block copper absorption, weaken immune function and lower HDL cholesterol, and that food alone is unlikely to supply that much. The 50 mg used in the alopecia study sits above that limit.

Zinc can interact with quinolone and tetracycline antibiotics and with penicillamine, according to the NIH, and some diuretics lower blood zinc by raising the amount lost in urine. If you take any of these and are thinking about zinc for your hair, that is worth raising with whoever prescribes them. We have no card on zinc for hair in pregnancy. That is a gap in what we found, not a sign of safety.

What expert bodies say

The NIH Office of Dietary Supplements is the only expert body on our cards here. It treats hair loss as a sign of zinc deficiency, and it gives the upper limit and the drug interactions above. We found no dermatology or nutrition body that recommends zinc for hair loss in people with normal zinc status.

How we searched

What would change this answer

• A randomized, placebo-controlled trial of zinc alone in people with alopecia areata or chronic shedding and low blood zinc, with hair counts as the outcome. We found none, in print or registered.
• The same trial in people with normal zinc, which is the group most supplements are sold to.
• A supplement trial with a zinc-only arm. The blends that do show an effect on hair density cannot tell anyone which ingredient did the work.

Sources

1. ev-znh-01 · Meta-analysis or systematic review · systematic review and meta-analysis of randomized controlled trials, open-label and proof-of-concept studies · n = 14 studies, 967 participants
   Meta-analysis demonstrated significant improvements with oral supplements versus placebo: reduced telogen hair density (mean difference [MD] -5.91, 95% confidence interval [CI] -6.74 to -5.08, p < 0.00001), increased anagen hair density (MD 10.48, 95% CI: 8.81 to 12.14, p < 0.00001), and reduced telogen proportion (MD 3.08, 95% CI: -3.35 to -2.81, p < 0.00001).
   
   Who: adults (18 years or older) with alopecia or hair thinning taking commercial oral nutraceuticals
   Effect: telogen hair density MD -5.91 (95% CI -6.74 to -5.08); anagen hair density MD 10.48 (95% CI 8.81 to 12.14); total hair count not significant (p = 0.06)
   Certainty: Products: Nutrafol, Viviscal, Nourkrin, Lambdapil, etc., mixtures; there is no separate zinc arm. The authors ask for independent studies.
   J Cosmet Dermatol, 2026 · checked 2026-10-07 · we read the abstract
2. ev-znh-02 · Meta-analysis or systematic review · systematic review and network meta-analysis of randomized controlled trials with GRADE · n = 19 RCTs, 1658 patients
   A total of 19 RCTs involving 1,658 AGA patients were included, with 894 patients in the supplement group and 764 in the control group.
   
   Who: patients with androgenetic alopecia in randomized controlled trials of dietary supplements
   Effect: no zinc arm among 16 supplements (full text checked); Nutrafol, apple extract, tocotrienols and pumpkin seed oil raised hair density vs placebo
   Certainty: The PMC full text was checked for "zinc": no matches. So the newest RCT synthesis for AGA simply has no zinc.
   Front Nutr, 2025 · checked 2026-10-07 · we read the abstract
3. ev-znh-03 · Meta-analysis or systematic review · Cochrane systematic review and meta-analysis of randomized controlled trials · n = 34 studies, 8526 participants; adverse events for treatment: 16 studies, 2084 participants
   There is probably an increase in the risk of non-serious adverse events when zinc is used for cold treatment (RR 1.34, 95% CI 1.15 to 1.55; I2 = 44%; 2084 participants, 16 studies; moderate-certainty evidence); no treatment study provided information on serious adverse events.
   
   Who: children or adults in randomized controlled trials of zinc versus placebo for the common cold
   Effect: non-serious adverse events RR 1.34 (95% CI 1.15 to 1.55), moderate certainty; zinc gluconate doses 45 to 276 mg/day
   Certainty: Zinc safety in RCTs overall: adverse effects (taste, nausea) are not serious but more frequent. Not about hair but about the cost of taking it.
   Cochrane Database Syst Rev, 2024 · checked 2026-10-07 · we read the abstract
4. ev-znh-04 · Meta-analysis or systematic review · systematic review and meta-analysis of randomized controlled trials with GRADE, commissioned by WHO · n = 38 RCTs
   A significant number of children in the zinc group compared to placebo experienced vomiting (RR = 1.46; 95% CI = 1.22, 1.76; moderate certainty of evidence), however, there were few vomiting episodes in low-dose zinc group compared to high-dose (RR = 0.80; 95% CI = 0.72, 0.89; moderate certainty of evidence).
   
   Who: children aged less than 10 years with acute or persistent diarrhea
   Effect: vomiting RR 1.46 (95% CI 1.22 to 1.76); low vs high dose RR 0.80 (95% CI 0.72 to 0.89); moderate certainty
   Certainty: For children the zinc dose matters: vomiting is dose-dependent. Transferred as a caveat about "zinc for hair" in children.
   J Glob Health, 2024 · checked 2026-10-07 · we read the abstract
5. ev-znh-05 · Observational data · systematic review and meta-analysis of case-control studies · n = 34 papers, 4931 participants; zinc: 10 studies, 878 participants
   The results of meta-analysis demonstrated patients with AA had a lower serum level of vitamin D (SMD = -0.93 ng/mL, 95% CI = 0.168-0.747, p < 0.05) and serum zinc (SMD = -0.69 μg/dL, 95% CI = -0.99 to -0.39, p < 0.05) than the healthy controls.
   
   Who: patients with alopecia areata versus healthy controls
   Effect: serum zinc SMD -0.69 (95% CI -0.99 to -0.39); I2 = 76.5%
   Certainty: Association, not cause: lower zinc may be a consequence of inflammation. High heterogeneity. The authors' conclusion about treatment is a hypothesis.
   J Cosmet Dermatol, 2025 · checked 2026-10-07 · we read the abstract
6. ev-znh-06 · Observational data · meta-analysis of case-control studies · n = 10 articles, 764 subjects
   This meta-analysis suggests that low serum levels of zinc and selenium seem to be important risk factors for AA.
   
   Who: patients with alopecia areata versus healthy controls
   Effect: serum zinc lower (P < 10^-4); copper P = 0.81, iron P = 0.36, ferritin P = 0.37, magnesium P = 0.07
   Certainty: Consistent with ev-znh-05; "risk factor" is the authors' wording, the design allows only an association.
   J Dermatol, 2017 · checked 2026-10-07 · we read the abstract
7. ev-znh-07 · Observational data · systematic review and meta-analysis of observational studies · n = 18 studies, 2538 patients
   Hair loss is common after MBS especially in younger women, and those with low serum levels of zinc, folic acid, and ferritin.
   
   Who: patients after metabolic and bariatric surgery
   Effect: hair loss incidence 57% (95% CI 42 to 71%); serum zinc SMD -1.13 (95% CI -2.27 to 0.01, p = 0.05); folic acid SMD -0.88; ferritin SMD -0.22
   Certainty: The association with zinc is borderline significant (CI touches zero). A group where zinc deficiency is real.
   Obes Surg, 2021 · checked 2026-10-07 · we read the abstract
8. ev-znh-08 · Observational data · systematic review of observational studies · n = —
   Routine monitoring of zinc levels is hence unnecessary for asymptomatic patients after RYGB and should be reserved for patients with skin lesions, hair loss, pica, dysgeusia, hypogonadism or erectile dysfunction in male patients, and unexplained iron deficiency anaemia.
   
   Who: patients after Roux-en-Y gastric bypass
   Effect: routine zinc monitoring not needed in asymptomatic patients; test when hair loss, skin lesions, pica, dysgeusia or hypogonadism appear
   Certainty: Society positions diverge: BOMSS advises routine monitoring, the American ones only for signs (from the abstract text).
   Obes Surg, 2017 · checked 2026-10-07 · we read the abstract
9. ev-znh-09 · Observational data · systematic review without meta-analysis, mixed randomized and non-randomized studies · n = 30 articles (17 RCTs, 11 non-randomized clinical studies, 2 case series)
   Studies of nutritional interventions with the highest-quality evidence showed the potential benefit of Viviscal, Nourkrin, Nutrafol, Lamdapil, Pantogar, capsaicin and isoflavone, omegas 3 and 6 with antioxidants, apple nutraceutical, total glucosides of paeony and compound glycyrrhizin tablets, zinc, tocotrienol, and pumpkin seed oil.
   
   Who: individuals with alopecia or hair loss without a known baseline nutritional deficiency
   Effect: qualitative only: zinc named among interventions with potential benefit; adverse effects rare and mild
   Certainty: No full text in PMC (no_pmc): which zinc study and of what design cannot be seen from the abstract. Hence C.
   JAMA Dermatol, 2023 · checked 2026-10-07 · we read the abstract
10. ev-znh-10 · Observational data · uncontrolled open-label before-after trial, no placebo group · n = 15
    Positive therapeutic effects were observed for 9 out of 15 patients (66.7%) although this was not statistically significant.
    
    Who: alopecia areata patients with a low serum zinc level (70 mcg/dl or less), disease for at least 6 months
    Effect: regrowth in 9 of 15 (66.7%), not significant; serum zinc 56.9 to 84.5 mcg/dl
    Certainty: No control; in alopecia areata spontaneous regrowth is common. Dose 50 mg > UL 40 mg (ev-znh-14).
    Annals of Dermatology, 2009, 21(2):142-146, The Therapeutic Effect and the Changed Serum Zinc Level after Zinc Supplementation in Alopecia Areata Patients · checked 2026-10-07 · we read the abstract
11. ev-znh-11 · Observational data · retrospective cohort with propensity score matching · n = 289
    After PSM adjustment of demographic characteristics, no significant differences in elements, vitamins, or hormone levels were observed between the F1 and F2/3 groups.
    
    Who: patients with female pattern hair loss (150 grade F1, 139 grade F2/3)
    Effect: no significant difference in elements, vitamins or hormones after PSM; only disease duration predicted severity (OR 1.123, 95% CI 1.047 to 1.211)
    Certainty: Counterexample: the link of zinc with severity disappears after accounting for age and duration.
    Aesthetic Plast Surg, 2026 · checked 2026-10-07 · we read the abstract
12. ev-znh-12 · Observational data · case-control study · n = 100
    Significantly low levels of zinc were observed in serum as well as hair samples in group A compared to group B (p<0.05).
    
    Who: patients with chronic telogen effluvium and age- and gender-matched healthy controls, Karachi
    Effect: serum and hair zinc lower in cases (p < 0.05); hair and serum zinc correlated r = 0.310
    Certainty: Small sample, only p-values without absolute levels in the abstract.
    J Pak Med Assoc, 2024 · checked 2026-10-07 · we read the abstract
13. ev-znh-13 · Laboratory or animal data · literature review of case reports and case series · n = 231 patients from 190 articles
    Among the 174 AE patients who received zinc supplementation at various dosages, 159 (91.4%) demonstrated therapeutic efficacy, with 1-3 mg/kg/day as the most commonly used effective dosage.
    
    Who: pediatric patients (under 18 years) with acrodermatitis enteropathica reported in the literature
    Effect: response 159/174 (91.4%); zinc deficiency in 75.9%; zinc often ineffective when AE stems from metabolic disease
    Certainty: Where hair loss is caused by true zinc deficiency, zinc corrects it. Case series → D (open question §2).
    Front Nutr, 2025 · checked 2026-10-07 · we read the abstract
14. ev-znh-14 · Position of an expert body · agency fact sheet · n = —
    Doses of 50 mg of zinc or more over a period of weeks can inhibit copper absorption, reduce immune function, and lower high-density lipoprotein cholesterol levels; however, it is unlikely that a person would obtain this much zinc from food alone. The Tolerable Upper Intake Level for zinc is 40 mg for adults, and it ranges from 4 to 34 mg for infants, children, and adolescents, depending on age.
    
    Who: healthy individuals (ULs do not apply to people treated with zinc under a physician)
    Effect: UL 40 mg/day adults; 4 to 34 mg/day infants, children and adolescents; >=50 mg/day for weeks impairs copper absorption, immune function and HDL
    Certainty: The tail 50 mg/day from alopecia studies is already above the UL.
    NIH Office of Dietary Supplements, Zinc fact sheet for health professionals · checked 2026-10-07 · we read the section
15. ev-znh-15 · Position of an expert body · agency fact sheet · n = —
    Zinc may interact with certain medications, such as quinolone antibiotics, tetracycline antibiotics, and penicillamine. In addition, some diuretics can decrease serum zinc concentrations by increasing zinc excretion in urine.
    
    Who: people taking these medications regularly
    Effect: interactions: quinolone antibiotics, tetracycline antibiotics, penicillamine; thiazide-type diuretics increase zinc excretion
    Certainty: Who should be careful: antibiotics (separate in time), penicillamine.
    NIH Office of Dietary Supplements, Zinc fact sheet for health professionals · checked 2026-10-07 · we read the section
16. ev-znh-16 · Position of an expert body · agency fact sheet · n = —
    In older children, alopecia, delayed growth, and frequent infections become more prevalent.
    
    Who: infants, children and older adults with zinc deficiency
    Effect: alopecia listed as a sign of zinc deficiency in older children
    Certainty: Authority position: hair loss as a sign of deficiency, not as an indication for supplements in healthy people.
    NIH Office of Dietary Supplements, Zinc fact sheet for health professionals · checked 2026-10-07 · we read the section