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BetaPower

Also known as: Betaine, trimethylglycine, Betaine anhydrous, glycine betaine

Overview

Betaine, also known as trimethylglycine, is a naturally occurring compound found in various foods such as beets, spinach, and whole grains. It functions primarily as a methyl donor in critical biochemical pathways and as an osmoprotectant, helping cells maintain hydration and integrity under stress. As a dietary supplement, betaine is commonly used to enhance exercise performance, particularly muscle strength, and to support overall cellular function, including liver health and homocysteine metabolism. Research on betaine supplementation is moderately mature, with a growing body of randomized controlled trials and meta-analyses. While some studies demonstrate clear benefits on muscle strength and power, evidence regarding its effects on body composition remains inconsistent or negative. It is generally recognized for its role in methylation and osmotic regulation within the body.

Benefits

Betaine supplementation offers several evidence-based benefits, primarily in the realm of exercise performance. A high-quality systematic review and meta-analysis of 17 randomized controlled trials (RCTs) involving 317 participants found that chronic betaine supplementation (≥7 days) significantly improves maximal muscular strength, particularly lower body strength, with a standardized mean difference (SMD) of 0.47 (95% CI 0.04 to 0.89). The same meta-analysis also reported a significant improvement in vertical jump height (SMD 0.36, 95% CI 0.03 to 0.69) after excluding a low-quality study. These benefits are most pronounced in individuals engaged in strength and power activities. However, a 2021 systematic review and meta-analysis concluded that betaine supplementation does not significantly improve body composition indices such as body mass, BMI, fat mass, body fat percentage, or fat-free mass. Evidence for other performance measures like cycling sprint power, bench press power, and muscular endurance is inconsistent or lacking, and it has not been identified as a top-performing ergogenic aid for elite combat sports athletes compared to other supplements like caffeine or beta-alanine.

How it works

Betaine exerts its effects through two primary mechanisms: as a methyl donor and as an osmolyte. As a methyl donor, betaine participates in the methionine-homocysteine cycle, facilitating crucial methylation reactions vital for various cellular functions, including DNA synthesis and neurotransmitter production. This role may contribute to enhanced muscle protein synthesis. As an osmolyte, betaine helps protect cells against osmotic stress by regulating cell volume and maintaining cellular hydration. This osmoprotective function is thought to contribute to improved muscle cell function and endurance during exercise. The combination of enhanced methylation and cellular hydration is proposed to be responsible for the observed improvements in muscle strength and power. Oral supplementation generally results in good bioavailability, though specific pharmacokinetics can vary.

Side effects

Betaine supplementation is generally considered safe and well-tolerated when taken at typical doses, with no serious adverse effects reported in randomized controlled trials at doses up to approximately 6 grams per day. The most common side effects, though rare, may include mild gastrointestinal discomfort, such as nausea or diarrhea. There are no significant drug interactions or contraindications that have been well-documented in the scientific literature. However, the safety of betaine in specific populations, such as pregnant or breastfeeding women, children, or individuals with severe renal impairment, has not been well established through extensive research. As with any supplement, individuals with pre-existing medical conditions or those taking other medications should consult a healthcare professional before initiating betaine supplementation to ensure its appropriateness and safety.

Dosage

Effective dosages of betaine in research studies have ranged from 1.25 grams to 6 grams per day. For performance enhancement, benefits on strength have been consistently observed after at least 7 days of continuous supplementation. An optimal dosing strategy for performance appears to be around 2.5 grams taken twice daily, although specific recommendations may vary based on individual needs and goals. The timing of betaine intake relative to exercise is not considered critical for its chronic effects; consistent daily intake is recommended to achieve and maintain the desired benefits. Betaine does not require specific cofactors for absorption, but adequate hydration is important to support its osmolyte function within cells. There are no widely established upper limits or safety thresholds beyond the typical effective doses, but adherence to recommended dosages is advised.

FAQs

Does betaine improve muscle strength?

Yes, high-quality evidence suggests betaine supplementation, especially after at least 7 days of use, can significantly improve maximal muscular strength, particularly in the lower body.

Does it help with fat loss or body composition?

Current scientific evidence does not support significant effects of betaine supplementation on body composition, including fat mass, lean mass, or body fat percentage.

Is it safe?

Betaine is generally considered safe and well-tolerated at typical dosages (up to 6g/day), with rare reports of mild gastrointestinal discomfort. No serious adverse effects are commonly reported.

When should it be taken?

Daily supplementation is recommended for chronic effects. The timing relative to workouts is not critical, as benefits accumulate over time rather than acutely.

Are benefits immediate?

No, the ergogenic benefits of betaine, particularly for strength and power, typically appear after at least one week of continuous daily use, not immediately after a single dose.

Research Sources

https://www.cambridge.org/core/journals/british-journal-of-nutrition/article/betaine-supplementation-fails-to-improve-body-composition-a-systematic-review-and-metaanalysis/77F1B60A77203E0903381DE16937EA02 – This systematic review and meta-analysis of 9 RCTs concluded that betaine supplementation does not significantly improve body composition indices such as body mass, BMI, fat mass, or fat-free mass in adults. The study highlights that despite some claims, betaine's role in body composition alteration is not supported by current evidence.
https://pubmed.ncbi.nlm.nih.gov/39514262/ – This systematic review and meta-analysis of 17 RCTs (317 participants) found that chronic betaine supplementation (≥7 days) significantly improves maximal muscular strength, especially lower body strength, and vertical jump height. The study provides strong evidence for betaine's ergogenic effects on strength and power performance.
https://www.nature.com/articles/s41598-024-84359-3 – This network meta-analysis evaluated the efficacy of various ergogenic aids for combat sports athletes. It concluded that betaine was not among the top-performing supplements, with caffeine, beta-alanine, and sodium bicarbonate showing more significant benefits for elite combat sports performance.
https://pubmed.ncbi.nlm.nih.gov/28426517/ – This narrative review examined the existing literature on betaine's ergogenic effects. It concluded that there is insufficient evidence to support a clear and consistent ergogenic effect of betaine on strength and power, highlighting the need for more robust and consistent research at the time of publication.