Beta-Alanine

Table of Contents

1. What Beta-Alanine Is
2. How It Works (Carnosine & Acid Buffering)
3. What the Evidence Shows (Exercise Performance)
4. Doses Used in Studies
5. The Tingling (Paresthesia)
6. Safety & Considerations
7. Key Research Papers
8. Connections
9. Featured Videos

What Beta-Alanine Is

Beta-alanine is a naturally occurring amino acid. Chemically it is a beta-amino acid, a slightly unusual structure compared with the alpha-amino acids that make up proteins. It is classed as non-essential, meaning the body can produce some on its own; meat, poultry, and fish also supply it, mainly bound in carnosine and related dipeptides.

Unlike most amino acids, beta-alanine is not used to build muscle protein, and it is not a fuel. Its importance comes down to a single job: it is the rate-limiting building block muscle needs to make a compound called carnosine (Hill and colleagues 2007; Baguet and colleagues 2009). Because of that one role, beta-alanine is used mainly as a sports-nutrition supplement, to raise muscle carnosine.

How It Works (Carnosine & Acid Buffering)

Inside muscle, beta-alanine joins with another amino acid, histidine, to form carnosine (a dipeptide — two amino acids linked together). Muscle usually has plenty of histidine but relatively little beta-alanine; as Hill and colleagues (2007) put it, muscle carnosine synthesis “is limited by the availability of beta-alanine.” That is why supplementing beta-alanine raises carnosine.

So why does carnosine matter? During hard, intense exercise, muscles produce hydrogen ions, which make the muscle more acidic. That rising acidity is one of the factors that contributes to fatigue. Carnosine acts as an intracellular pH buffer (ISSN position stand, Trexler and colleagues 2015) — it takes up hydrogen ions and helps keep the muscle's internal acid–base balance more stable, which is the proposed mechanism for its effect on high-intensity exercise.

Studies that take muscle samples have measured the rise directly. Harris and colleagues (2006) found muscle carnosine increases estimated at 42.1% and 64.2% after 4 weeks of 3.2 and 6.4 g of beta-alanine per day. Hill and colleagues (2007) found increases of 58.8% after 4 weeks and 80.1% after 10 weeks, and the improvement in high-intensity cycling capacity in that study followed the increase in muscle carnosine.

What the Evidence Shows (Exercise Performance)

Beta-alanine is one of the more studied performance supplements. The measured effect is small, and it depends on the kind of exercise.

The ISSN position stand (Trexler and colleagues 2015) concluded that daily supplementation with 4 to 6 g of beta-alanine for at least 2 to 4 weeks “has been shown to improve exercise performance, with more pronounced effects in open end-point tasks/time trials lasting 1 to 4 min in duration,” and that more research is needed on endurance performance beyond 25 minutes. A 2012 meta-analysis by Hobson and colleagues (15 studies, 360 participants) found a median improvement of 2.85% in the exercise measures tested. Exercise lasting 60 to 240 seconds improved, as did exercise lasting more than 240 seconds, while there was no benefit for exercise lasting under 60 seconds.

A larger 2017 meta-analysis by Saunders and colleagues (40 studies, 1,461 participants) found a small overall effect size of 0.18. Exercise duration significantly changed the size of the effect, and within exercise lasting 0.5 to 10 minutes the effect was larger for tests of exercise capacity than for performance tests. Training status and the total amount of beta-alanine taken did not change the effect, and co-supplementation with sodium bicarbonate gave the largest effect size compared with placebo.

Doses Used in Studies

Beta-alanine acts by accumulation, not as an acute pre-workout effect. The rise in muscle carnosine builds over weeks of daily intake; Stellingwerff and colleagues (2012) found that the increase depended only on the total amount of beta-alanine consumed, within daily intakes of 1.6 to 3.2 g.

The ISSN position stand describes 4 to 6 g daily for at least 2 to 4 weeks as the intake that has been shown to improve exercise performance. Individual trials have used 3.2 and 6.4 g per day, given as multiple doses of 400 or 800 mg (Harris and colleagues 2006). The ISSN reports that the tingling can be attenuated by divided lower doses (1.6 g) or a sustained-release formula. In one study, carnosine loading in the soleus muscle was greater when beta-alanine was taken with meals (+64%) than between meals (+41%) (Stegen and colleagues 2013). After supplementation stops, muscle carnosine declines slowly, at about 2 to 4% per week (Baguet and colleagues 2009).

Beta-alanine is sold on its own and is also a common ingredient in pre-workout blends. The tingling felt soon after such a product reflects beta-alanine acting on skin sensory neurons as its blood level peaks, while the rise in muscle carnosine that the ISSN links to performance builds over at least 2 to 4 weeks.

The Tingling (Paresthesia)

Beta-alanine's best-known side effect is a tingling, prickling sensation on the skin that comes on soon after a dose. The medical term for this pins-and-needles feeling is paresthesia. A 2019 systematic risk assessment found paresthesia to be the only reported side effect of beta-alanine, with an odds ratio of 8.9 compared with placebo (Dolan and colleagues 2019).

In mice, Liu and colleagues (2012) showed that beta-alanine triggers itch-related behaviour through MrgprD, a receptor on a subset of sensory neurons that supply the skin; in people, beta-alanine injected into the skin caused itch without the wheal or flare that histamine produces. In a trial in 11 healthy adults, Décombaz and colleagues (2012) found that “pins and needles” appeared on the skin of the arms and trunk after 1.6 g of beta-alanine in solution, peaked about 15 minutes after the dose, and followed the rise and fall of blood beta-alanine.

Studies tie the tingling to larger single doses: Décombaz and colleagues note that doses larger than 800 mg commonly cause it. In their trial, slow-release tablets gave a lower blood peak and sensory symptoms that could not be told apart from placebo, and the ISSN position stand states that the tingling can be attenuated by divided lower doses (1.6 g) or a sustained-release formula. None of the sources cited here studied taking beta-alanine with food as a way to reduce the tingling.

Safety & Considerations

The ISSN position stand concludes that beta-alanine “currently appears to be safe in healthy populations at recommended doses” and that the only reported side effect is paraesthesia. The 2019 risk assessment by Dolan and colleagues (101 human and 50 animal studies) found paresthesia to be the only reported side effect, similar dropout rates with beta-alanine and placebo, and a small rise in the liver enzyme alanine aminotransferase that stayed well within clinical reference ranges. It concluded that beta-alanine “within the doses used in the available research designs, does not adversely affect those consuming it.”

Beta-alanine and taurine share a cell transporter. In rodents, the Dolan review found an effect of beta-alanine on taurine concentration only when the daily dose was 3% or more beta-alanine in drinking water; in the pooled human data there was no effect on muscle taurine. In a 24-week trial, 6.4 g per day of sustained-release beta-alanine did not significantly affect muscle taurine or blood markers of kidney, liver, and muscle function in healthy men (Saunders and colleagues 2020). That is the longest controlled human safety trial cited here, so there is less information on longer use.

The sources cited here report no safety data for pregnancy, breastfeeding, or children, and no drug interactions; the absence of data is a gap, not evidence of harm or of safety. Dietary supplements are not reviewed for safety and effectiveness before sale in the way medicines are. Decisions about supplements alongside prescription medicines or a health condition belong with a clinician. The full safety picture is on the Safety & Stacking page.

Key Research Papers

1. Trexler ET, Smith-Ryan AE, Stout JR, et al. International Society of Sports Nutrition position stand: beta-alanine. Journal of the International Society of Sports Nutrition. 2015;12:30. — The major expert consensus paper: 4–6 g/day raises muscle carnosine and improves performance, most clearly in efforts lasting about 1–4 minutes. — doi:10.1186/s12970-015-0090-y
2. Hobson RM, Saunders B, Ball G, Harris RC, Sale C. Effects of β-alanine supplementation on exercise performance: a meta-analysis. Amino Acids. 2012;43(1):25–37. — Pooling 15 studies, beta-alanine gave a median 2.85% improvement; exercise lasting 60–240 seconds and over 240 seconds improved, exercise under 60 seconds did not. — doi:10.1007/s00726-011-1200-z
3. Saunders B, Elliott-Sale K, Artioli GG, et al. β-alanine supplementation to improve exercise capacity and performance: a systematic review and meta-analysis. British Journal of Sports Medicine. 2017;51(8):658–669. — A larger review (40 studies, 1,461 participants) found a small overall effect size of 0.18, with exercise duration moderating the effect. — doi:10.1136/bjsports-2016-096396
4. Harris RC, Tallon MJ, Dunnett M, et al. The absorption of orally supplied β-alanine and its effect on muscle carnosine synthesis in human vastus lateralis. Amino Acids. 2006;30(3):279–289. — Oral beta-alanine at 3.2 and 6.4 g/day for 4 weeks raised muscle carnosine by an estimated 42.1% and 64.2%. — doi:10.1007/s00726-006-0299-9
5. Hill CA, Harris RC, Kim HJ, et al. Influence of β-alanine supplementation on skeletal muscle carnosine concentrations and high-intensity cycling capacity. Amino Acids. 2007;32(2):225–233. — Muscle carnosine rose 58.8% at 4 weeks and 80.1% at 10 weeks, and the increase in high-intensity cycling capacity followed the carnosine increase. — doi:10.1007/s00726-006-0364-4
6. Dolan E, Swinton PA, Painelli VS, et al. A systematic risk assessment and meta-analysis on the use of oral β-alanine supplementation. Advances in Nutrition. 2019;10(3):452–463. — 101 human and 50 animal studies: paraesthesia the only reported side effect, a small ALT rise within reference ranges, no effect on human muscle taurine. — PubMed PMID: 30980076
7. Saunders B, Franchi M, de Oliveira LF, et al. 24-Week β-alanine ingestion does not affect muscle taurine or clinical blood parameters in healthy males. European Journal of Nutrition. 2020;59(1):57–65. — PubMed PMID: 30552505
8. Liu Q, Sikand P, Ma C, et al. Mechanisms of itch evoked by β-alanine. Journal of Neuroscience. 2012;32(42):14532–14537. — The MrgprD receptor finding is from mice. — PubMed PMID: 23077038
9. Décombaz J, Beaumont M, Vuichoud J, Bouisset F, Stellingwerff T. Effect of slow-release β-alanine tablets on absorption kinetics and paresthesia. Amino Acids. 2012;43(1):67–76. — PubMed PMID: 22139410 (erratum: Amino Acids 2013;45(4):1015)
10. Stellingwerff T, Anwander H, Egger A, et al. Effect of two β-alanine dosing protocols on muscle carnosine synthesis and washout. Amino Acids. 2012;42(6):2461–2472. — PubMed PMID: 21847611
11. Stegen S, Blancquaert L, Everaert I, et al. Meal and beta-alanine coingestion enhances muscle carnosine loading. Medicine & Science in Sports & Exercise. 2013;45(8):1478–1485. — PubMed PMID: 23439427
12. Baguet A, Reyngoudt H, Pottier A, et al. Carnosine loading and washout in human skeletal muscles. Journal of Applied Physiology. 2009;106(3):837–842. — PubMed PMID: 19131472

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Connections

• All Amino Acids
• Citrulline
• Alanine
• Histidine
• Carnitine
• Beta-Alanine for Endurance — why beta-alanine is biochemically nothing like L-alanine.
• Carnosine
• Carnosine: History and Discovery — how Gulewitsch identified beta-alanine as carnosine's unusual second building block in 1911.
• Alanine — Benefits Deep Dive — the alpha-isomer hub that contrasts the two molecules.
• BAIBA

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