What is the recommended dosage of HMB supplement per day?

The most widely studied and effective dose of CaHMB is 3 grams per day, typically divided into three 1 g doses taken with meals to maintain stable plasma concentrations. Some protocols time one dose within 30–60 minutes before exercise to attenuate acute muscle protein breakdown. Doses above 3 g/day have not demonstrated additional benefit in published trials.

How long does it take for HMB to work for muscle building?

Clinical trials generally observe measurable improvements in fat-free mass and strength within 3–6 weeks of consistent 3 g/day supplementation combined with resistance training. Muscle protein synthesis increases are detectable earlier, within days, based on isotopic tracer studies. Longer supplementation periods of 8–12 weeks produce the most robust changes in body composition outcomes.

Does HMB help prevent muscle loss in older adults?

Yes, CaHMB is one of the better-studied supplements for sarcopenia management, with RCT evidence showing preservation of lean mass and improved functional strength in elderly populations during periods of inactivity or caloric deficit. Its dual mechanism of stimulating mTOR-driven synthesis and suppressing ubiquitin-proteasome degradation is particularly relevant in aging muscle, where proteolysis is chronically elevated. Studies including clinical populations such as hospitalized patients show significant fat-free mass retention compared to placebo.

What is the difference between HMB-FA and CaHMB (calcium HMB)?

CaHMB (calcium salt form) and HMB free acid (HMB-FA) differ primarily in absorption kinetics: HMB-FA reaches peak plasma concentration in approximately 30 minutes versus 120 minutes for CaHMB, making the free acid form potentially more advantageous when timed acutely around exercise. However, CaHMB has a larger body of long-term clinical evidence supporting its efficacy and safety profile. NAXA PureHMB uses the calcium salt form, which is the most extensively validated form in published RCTs.

Can HMB be taken with creatine or protein supplements?

CaHMB is commonly co-supplemented with creatine monohydrate and whey protein, and no adverse interactions have been reported in research combining these agents. Some studies suggest an additive effect on lean mass when HMB is combined with creatine, though evidence for true synergy is limited. The calcium in CaHMB does not interfere with creatine uptake, and timing all three around workouts is a practical and evidence-consistent strategy.

Is NAXA PureHMB safe to use during cancer treatment or recovery?

Clinical evidence suggests HMB may benefit muscle mass and function in cancer patients, with a systematic review of 15 studies supporting its use as part of supportive care. However, you should consult your oncology team before adding NAXA PureHMB to your regimen, as individual circumstances and drug interactions vary. The calcium form in NAXA PureHMB is generally well-tolerated, but timing relative to your specific cancer medications should be discussed with your healthcare provider.

Can NAXA PureHMB help maintain muscle strength in chronic lung disease or bronchiectasis?

Yes, clinical research demonstrates that HMB improves handgrip strength and fat-free mass in patients with bronchiectasis and other clinical populations. A randomized controlled trial (PMID: 26522923) specifically showed measurable gains in muscle function in this patient group. NAXA PureHMB's calcium form provides the same active HMB compound studied in these clinical populations.

How much does NAXA PureHMB increase muscle protein synthesis in trained athletes?

Research shows that HMB increases muscle protein synthesis by approximately 1.39% per day in resistance-trained adults, based on strong evidence from randomized controlled trials. While this may seem modest, this daily increase compounds over weeks of consistent training and supplementation. This makes NAXA PureHMB particularly relevant for athletes already engaging in regular resistance training who are seeking incremental performance improvements.

NAXA PureHMB (Calcium β-hydroxy-β-methylbutyrate)

NAXA PureHMB delivers calcium β-hydroxy-β-methylbutyrate (CaHMB), a leucine metabolite that suppresses muscle protein breakdown while stimulating protein synthesis via the mTOR pathway. It is clinically studied for preserving lean mass, enhancing strength, and reducing exercise-induced muscle damage in both athletes and clinical populations.

Category: Other Evidence: 2/10 Tier: Strong (multiple RCTs/meta-analyses)

NAXA PureHMB (Calcium β-hydroxy-β-methylbutyrate) — Hermetica Encyclopedia

Origin & History

NAXA PureHMB is a branded form of Calcium β-hydroxy-β-methylbutyrate (Ca-HMB), a metabolite of the essential amino acid leucine. It is synthetically produced rather than extracted from natural sources, belonging to the chemical class of branched-chain amino acid derivatives. HMB is typically manufactured for supplementation purposes and does not have a specific organism or plant source.

Historical & Cultural Context

HMB has no evidence of historical or traditional use in medicine systems. It is a modern leucine metabolite used as a supplement for athletes and clinical nutrition since the late 20th century, without roots in herbal or folk practices.

Health Benefits

• Increases muscle protein synthesis by 1.39% per day in resistance-trained adults (Strong evidence - RCT, PMC: 6876270)
• Improves handgrip strength and fat-free mass in clinical populations including bronchiectasis patients (Strong evidence - RCT, PMID: 26522923)
• Benefits muscle mass and function in cancer patients (Moderate evidence - systematic review of 15 studies, PMID: 35301826)
• Enhances body composition and strength in elderly, especially bedridden or sedentary individuals (Strong evidence - meta-analysis, PMID: 33709969)
• Shows trend toward improved liver function in malnourished cirrhosis patients (Moderate evidence - RCT, PMID: 35684144)

How It Works

CaHMB activates the mTOR (mechanistic target of rapamycin) signaling cascade, upregulating p70S6 kinase and 4E-BP1 phosphorylation to drive muscle protein synthesis. Simultaneously, it inhibits the ubiquitin-proteasome pathway, reducing muscle protein degradation by suppressing MAFbx/atrogin-1 and MuRF-1 expression. CaHMB also stabilizes sarcolemmal integrity by incorporating into cholesterol biosynthesis, reducing creatine kinase leakage as a marker of muscle membrane damage.

Scientific Research

Multiple RCTs and meta-analyses support HMB's muscle-preserving effects, including a double-blind RCT (n=43) in cirrhosis patients showing improved handgrip strength (PMID: 35684144) and a meta-analysis demonstrating improved muscle mass, strength, and physical function at 3g/day dosing (PMC: 12003145). A comprehensive meta-analysis of 10 RCTs (n=421) found no adverse effects on lipid profiles (PMID: 39385778).

Clinical Summary

A randomized controlled trial (PMC: 6876270) demonstrated that CaHMB supplementation increases muscle protein synthesis by 1.39% per day in resistance-trained adults, representing a meaningful anabolic stimulus. An RCT in bronchiectasis patients (PMID: 26522923) showed significant improvements in handgrip strength and fat-free mass, indicating clinical utility beyond healthy athletic populations. Meta-analyses across multiple RCTs consistently support benefits in fat-free mass retention during caloric restriction and in aging-related sarcopenia. Evidence strength is rated strong for muscle protein synthesis and functional outcomes, though effect sizes tend to be modest in already well-trained individuals.

Nutritional Profile

NAXA PureHMB (Calcium β-hydroxy-β-methylbutyrate) is a purified bioactive compound supplement, not a whole food ingredient. Primary active compound: β-hydroxy-β-methylbutyrate (HMB) as calcium salt, typically dosed at 1.5–3g HMB free acid equivalent per day in clinical studies. Calcium content: approximately 125–250mg elemental calcium per 3g dose of calcium HMB salt (CaHMB), contributing meaningfully to daily calcium requirements. Macronutrient profile is negligible — essentially zero fat, carbohydrate, and protein per functional dose. No dietary fiber, vitamins, or other micronutrients present. Bioactive compound: HMB is an endogenous leucine catabolite; only ~5% of dietary leucine is naturally converted to HMB in vivo, making supplementation the primary route to therapeutic concentrations. Bioavailability is high — the free acid form (HMB-FA) reaches peak plasma concentration faster (~30 min) than the calcium salt form (CaHMB, ~60–120 min), though total absorption is comparable between forms (~80–90% bioavailable). Plasma HMB concentrations following 3g CaHMB supplementation reach approximately 400–600 μmol/L at peak. The calcium HMB salt form provides slower but sustained plasma elevation, potentially advantageous for prolonged anabolic signaling. No significant caloric contribution per standard serving.

Preparation & Dosage

Clinically studied doses are typically 3 g/day of HMB (as Ca-HMB or HMB-FA), divided into 1-3 doses, often in oral nutritional supplements or powder/sachet form. Studies used standardized Ca-HMB at 1.5 g twice daily or HMB-FA at 1 g three times daily. Consult a healthcare provider before starting any new supplement.

Synergy & Pairings

Whey Protein, Creatine Monohydrate, Vitamin D3, L-Leucine, Beta-Alanine

Safety & Interactions

CaHMB is well-tolerated in doses up to 3 g/day across trials lasting up to 12 months, with no clinically significant adverse events reported in healthy adults. The calcium component (~450 mg elemental calcium per 3 g dose) should be considered in individuals managing hypercalcemia or those on calcium-sensitive medications such as thiazide diuretics or digoxin. No major drug interactions have been formally established, but caution is warranted in patients taking bisphosphonates, as calcium may reduce their absorption if taken simultaneously. Safety data in pregnant or lactating women is insufficient, and use during pregnancy is not recommended without medical supervision.