How Does Vitamin B5 (Pantothenic Acid) Support Hair Strength and Thickness?

Vitamin B5, also known as pantothenic acid, is a water-soluble vitamin that plays a central role in cellular energy production and lipid metabolism. Because hair follicles are among the most metabolically active structures in the human body, researchers have long questioned whether pantothenic acid contributes to hair strength, density, and overall follicle health. The scientific literature suggests that vitamin B5 supports hair primarily by enabling energy production within follicle cells, maintaining normal skin barrier function, and participating in biochemical pathways essential for keratin synthesis. However, the strength of the evidence varies depending on whether the research was conducted in animals, cell cultures, or humans.

The Biological Role of Pantothenic Acid in Hair Follicles

Pantothenic acid is a precursor of coenzyme A, a molecule required for fatty acid metabolism and the synthesis of cholesterol, steroid hormones, and acetylcholine. Coenzyme A enables cells to convert carbohydrates, fats, and proteins into usable energy. Hair follicle matrix cells, which generate the hair shaft, divide rapidly and therefore require a continuous energy supply. According to the National Institutes of Health Office of Dietary Supplements, pantothenic acid deficiency is rare in humans but can cause fatigue, neurological symptoms, and skin irritation, reflecting its central metabolic role (NIH, 2022).

The outermost layer of hair, known as the cuticle, relies on structural proteins called keratins. Keratins are rich in sulfur-containing amino acids and require adequate cellular metabolism for proper assembly. Although pantothenic acid does not directly form keratin, its involvement in coenzyme A production supports the metabolic processes that allow keratin-producing cells to function efficiently.

Research published in the Journal of Investigative Dermatology in 2003 demonstrated that human keratinocytes, which are the main cell type in the outer layer of the skin and hair follicle, use a sodium-dependent multivitamin transporter to absorb nutrients including pantothenate (Subramanian et al., 2003). This laboratory study was conducted in cultured human keratinocyte cells. Researchers measured vitamin uptake using radiolabeled compounds and transporter inhibition assays. The results showed saturable transport, meaning the cells actively regulate vitamin absorption. A limitation of this study is that it was conducted in vitro, meaning outside the human body, so it cannot confirm clinical effects on hair growth. However, it establishes that follicle-related cells can absorb and utilize pantothenic acid.

What Happens When Vitamin B5 Is Deficient?

Much of the strongest evidence linking pantothenic acid to hair comes from animal deficiency studies conducted in the mid-20th century. In 1941, a controlled feeding experiment published in Experimental Biology and Medicine examined mice placed on purified diets lacking pantothenic acid and inositol (Morgan & Simms, 1941). The population consisted of laboratory mice. The duration varied across feeding cycles, generally several weeks. Hair loss, or alopecia, developed in mice deprived of pantothenic acid. Researchers evaluated hair loss through visible clinical observation and regrowth after nutrient reintroduction. Restoration of pantothenic acid corrected the alopecia. A limitation of this study is that it involved animals on artificial diets, which may not reflect typical human nutrition. Nonetheless, it demonstrated that severe deficiency can impair hair maintenance.

Similarly, a 1951 study in the Journal of Animal Science investigated pantothenic acid deficiency in baby pigs (Wiese et al., 1951). Young pigs were fed diets deficient in calcium pantothenate. Over several weeks, animals developed dermatitis, poor growth, and alopecia. Supplementation with 10–20 mg daily restored normal growth and hair condition. Outcomes were measured by weight gain, appetite, and visible dermatological recovery. A criticism is that agricultural animal models may not translate directly to humans, and deficiency levels were extreme. However, the findings reinforce that pantothenic acid is necessary for normal hair and skin health.

These deficiency studies confirm that vitamin B5 is required to prevent hair loss in cases of severe nutritional deprivation. In modern developed populations, however, such deficiencies are uncommon.

Pantothenic Acid and Hair Follicle Cell Proliferation

More recent mechanistic research has explored whether pantothenic acid actively stimulates hair follicle growth beyond simply preventing deficiency. A 2020 study published in Life Sciences examined the effects of pantothenic acid on dermal papilla cells isolated from American mink hair follicles (Zhang et al., 2020). Dermal papilla cells regulate the hair growth cycle and influence hair thickness. The study used cultured follicle cells treated with varying concentrations of pantothenic acid for several days. Researchers measured cell proliferation, migration, and gene expression using molecular assays.

The investigators found that a concentration of 20 micrograms per milliliter increased dermal papilla cell proliferation and upregulated growth factors such as insulin-like growth factor-1 and vascular endothelial growth factor. These growth factors are known to support the anagen phase, which is the active growth stage of the hair cycle. The study duration ranged from 24 to 72 hours in cell culture experiments. A key limitation is that the research was conducted in mink cells rather than human follicles, and the results were not tested in living animals or human subjects. Therefore, while the findings suggest a biological pathway through which pantothenic acid may enhance hair thickness, clinical confirmation in humans is lacking.

Evidence from Human Clinical Studies

Direct human trials isolating pantothenic acid alone are limited. However, combination supplements containing pantothenic acid have been studied. A double-blind, placebo-controlled trial published in 2007 evaluated a supplement containing L-cystine, medicinal yeast, and pantothenic acid in 30 women with telogen effluvium, a condition characterized by excessive shedding (Lengg et al., 2007). Participants were treated for six months. Hair growth was measured using digital epiluminescent microscopy, a method called TrichoScan that calculates the proportion of hairs in the anagen phase.

The treated group showed a statistically significant increase in the anagen hair rate compared to placebo. The method of evaluation was objective digital imaging, which strengthens reliability. However, pantothenic acid was only one component of the supplement, so its independent contribution cannot be determined. The study was also funded by the supplement manufacturer, which introduces potential bias.

In 2012, the European Food Safety Authority evaluated health claims linking a vitamin combination including pantothenic acid to hair maintenance (EFSA Panel on Dietetic Products, Nutrition and Allergies, 2012). After reviewing submitted evidence, the panel concluded that a cause-and-effect relationship had not been established. The primary criticism was that the provided study did not sufficiently isolate the tested nutrient combination. This regulatory review highlights that evidence for pantothenic acid as a stand-alone hair growth enhancer remains insufficient.

Does Vitamin B5 Increase Hair Thickness?

The available data suggest that pantothenic acid supports hair strength primarily by ensuring normal follicle metabolism rather than acting as a powerful growth stimulant. In cases of deficiency, supplementation restores normal hair structure. In cell studies, pantothenic acid enhances dermal papilla activity and growth factor expression. In combination human trials, it may contribute to improved anagen rates in diffuse shedding conditions.

However, for individuals with androgenetic alopecia, which is driven mainly by the hormone dihydrotestosterone, there is no strong evidence that pantothenic acid alone reverses follicle miniaturization. According to dermatological reviews such as Nutrition and Hair by Finner (2013), supplementation is most effective when correcting a documented deficiency rather than as a general growth booster.

User Experiences

Within the Tressless community, discussions about vitamin B5 often appear alongside conversations about biotin, B-complex vitamins, and combination hair supplements. In community threads such as “B5 (Pantothenic acid), B7 (Biotin), B12” and supplement stack discussions, users frequently report that vitamin B5 does not significantly regrow hair when used alone, especially in androgenetic alopecia. Several users mention combining B5 with established treatments such as minoxidil or finasteride rather than relying on it as a primary therapy.

Other community members describe improved scalp condition or reduced shedding when using multivitamin complexes containing pantothenic acid, though these reports are anecdotal and not controlled experiments. A recurring theme in user comments is that B-vitamins may help if there is an underlying deficiency but are unlikely to counteract hormonal hair loss without addressing dihydrotestosterone.

These community observations align with published research indicating that nutritional correction can restore normal hair cycling, but does not typically override genetically driven hair miniaturization.

Final Answer: How Does Vitamin B5 Support Hair Strength and Thickness?

Vitamin B5 supports hair strength and thickness by enabling cellular energy production through coenzyme A, maintaining normal lipid metabolism in the scalp, and supporting dermal papilla cell function. Severe deficiency clearly leads to hair loss in animal models, and correction restores normal growth. Laboratory studies show that pantothenic acid can stimulate follicle cell proliferation and growth factor expression. Human studies suggest possible benefit in diffuse shedding when used in combination supplements.

However, current evidence does not demonstrate that pantothenic acid alone significantly increases hair thickness in individuals without deficiency or in those with androgen-driven hair loss. Its primary contribution appears to be foundational metabolic support rather than direct stimulation of new hair growth.

References

EFSA Panel on Dietetic Products, Nutrition and Allergies (NDA). (2012). Scientific opinion on the substantiation of a health claim related to a combination of thiamin, riboflavin, niacin, pantothenic acid, pyridoxine, D-biotin and pumpkin seed oil and maintenance of normal hair. EFSA Journal, 10(7), 2807. https://doi.org/10.2903/j.efsa.2012.2807

Finner, A. M. (2013). Nutrition and hair: Deficiencies and supplements. Dermatologic Clinics, 31(1), 167–172. https://pubmed.ncbi.nlm.nih.gov/23159185/

Lengg, N., Heidecker, B., & Huber, R. (2007). Dietary supplement increases anagen hair rate in women with telogen effluvium: Results of a double-blind, placebo-controlled trial. Therapy, 4(1), 59–65. https://doi.org/10.2217/14750708.4.1.59

Morgan, A. F., & Simms, H. S. (1941). Relationship of pantothenic acid and inositol to alopecia in mice. Experimental Biology and Medicine, 46(4), 521–525. https://doi.org/10.3181/00379727-46-12065

National Institutes of Health Office of Dietary Supplements. (2022). Pantothenic acid fact sheet for health professionals. https://ods.od.nih.gov/factsheets/PantothenicAcid-HealthProfessional/

Subramanian, V. S., Said, H. M., & Marchant, J. S. (2003). Transport of biotin in human keratinocytes. Journal of Investigative Dermatology, 120(5), 821–826. https://pubmed.ncbi.nlm.nih.gov/12603856/

Wiese, A. C., Johnson, B. C., & Mitchell, H. H. (1951). Pantothenic acid deficiency in baby pigs. Journal of Animal Science, 10(1), 80–90. https://pubmed.ncbi.nlm.nih.gov/14814032/

Zhang, Y., et al. (2020). Pantothenic acid promotes dermal papilla cell proliferation in hair follicles of American minks via inhibitor of DNA binding 3/Notch signaling pathway. Life Sciences, 248, 117667. https://pubmed.ncbi.nlm.nih.gov/32304761/

Tressless Community. (2024). B5 (Pantothenic acid), B7 (Biotin), B12. Reddit r/tressless. https://reddit.com/r/tressless/comments/1bfpf07/b5_pantothenic_acid_b7_biotin_b12/

Tressless Community. (2024). MY Hair Loss Treatment Summary. Reddit r/tressless. https://reddit.com/r/tressless/comments/1d7ctyl/my_hair_loss_treatment_summary

Tressless Community. (2022). On a super stack, but still miniaturizing going strong??? Reddit r/tressless. https://reddit.com/r/tressless/comments/ze1z12/on_a_super_stack_but_still_miniaturizationg_going/