Performance Leucine+ by NB Pure is a specialized amino acid supplement featuring PepForm Leucine peptides as its core ingredient. This product is designed to leverage the metabolic and physiological roles of leucine, particularly in muscle protein synthesis, exercise recovery, and potential organ protection. The use of peptide-bound leucine—such as the tripeptide Leu-Ile-Lys—suggests an intent to enhance bioavailability and targeted biological activity compared to free-form leucine.
The 5 g dose of PepForm Leucine peptides significantly exceeds typical clinical doses of free leucine studied in human trials. While preclinical research indicates potential benefits in models of nephrolithiasis, metabolic dysfunction, and liver health, direct evidence supporting the efficacy of this specific peptide form in humans remains absent. Therefore, the product's value hinges on theoretical advantages of peptide delivery and extrapolation from free leucine studies, rather than robust human trials on the named ingredient.
Quick Summary
Transparency is good as the amount of the primary ingredient is clearly listed. However, the absence of information on other components or whether this is a single-ingredient product limits full assessment. No proprietary blend is indicated, supporting disclosure.
The primary ingredient is present in a substantial dose, but it falls below the clinically studied dose for exercise recovery (250 mg/kg) in most adults. Efficacy is further limited by the absence of human trials on PepForm Leucine peptides. Benefits are inferred from free leucine studies and preclinical models, resulting in moderate confidence.
PepForm Leucine peptides are presented as a high-absorption form, potentially offering +10–20% bioavailability advantage over free leucine. Peptide-bound amino acids generally have improved intestinal uptake, supporting a favorable bioavailability score despite lack of human pharmacokinetic data.
Leucine is safe for most adults at typical doses, but high intakes may disrupt amino acid balance, especially in liver disease. Caution is advised for individuals with MSUD or renal/liver impairment. Full safety profile is limited by lack of long-term human data on PepForm.
Suggested: 4 servings/day to reach clinical midpoint
Why Take This Product
Key Benefits
- Muscle Recovery Support: A clinical trial found that 250 mg/kg of leucine attenuated muscle damage markers following eccentric exercise in untrained men [1]. At 5 g, Performance Leucine+ likely meets or exceeds this dose for many adults, suggesting potential utility in post-exercise recovery.
- Potential Renal Protective Effects: In a rat model of oxalate kidney stones, the Leu-Ile-Lys tripeptide reduced oxidative stress and γ-glutamyltransferase activity, indicating a possible protective role in nephrolithiasis [4]. While not yet demonstrated in humans, this mechanism may be relevant for individuals at risk of kidney stones.
- Metabolic Regulation in Early Metabolic Disease: A systematic review reported that leucine supplementation at 90–140 mg/day improved glucose homeostasis in rodent models of diet-induced obesity when administered early in disease progression [3]. Though human translation is uncertain, this suggests a potential preventive metabolic role.
- Support in Liver Disease: BCAA deficiencies are common in advanced liver disease, and leucine supplementation has been used therapeutically to correct amino acid imbalances and support hepatocyte function [2]. This product may benefit patients under medical supervision.
- Enhanced Bioavailability via Peptide Form: Peptide-bound amino acids like those in PepForm may offer improved absorption kinetics compared to free amino acids, potentially leading to more efficient delivery and reduced gastrointestinal side effects.
Who Should Take This
Potential Side Effects
Ingredient Breakdown
The formulation centers on PepForm Leucine peptides, a proprietary peptide-bound form of leucine intended for superior absorption and targeted effects. Supporting ingredients are not listed, so analysis focuses solely on the primary component.
Primary Ingredients
PepForm Leucine peptides
Muscle protein synthesis, exercise recovery, metabolic and organ support
Dose of 5 g equates to approximately 71 mg/kg for a 70 kg adult, below the 250 mg/kg [1] used in exercise recovery trials. However, due to potential enhanced bioavailability of peptide-bound leucine, actual efficacy may differ. No human trials exist on PepForm specifically.
Bioactive peptide form of leucine with potential for enhanced absorption and targeted physiological effects. Preclinical studies suggest roles in reducing oxidative stress in kidney stone models and supporting metabolic health.
Practical Recommendations
- Use For Exercise Recovery: Given the evidence that 250 mg/kg leucine reduces post-exercise muscle damage [1], this product—assuming a 70 kg individual—delivers ~71 mg/kg, falling short of the clinical dose. Therefore, multiple servings may be needed to reach effective levels.
Is it Safe?
While leucine is safe for most people at typical doses, high intakes—especially in isolated form—require caution in certain populations. The absence of full formulation details limits comprehensive safety assessment, but known risks relate primarily to amino acid imbalances and metabolic disorders.
Safety & Considerations
- Medical Condition: Avoid in maple syrup urine disease (MSUD) due to impaired leucine metabolism.
- Medical Condition: Use with caution in liver or kidney disease; may alter amino acid balance and require medical supervision.
Reports for Similar Products
The Science
Efficacy is primarily determined by the dose and form of PepForm Leucine peptides. Although the 5 g dose exceeds many studied leucine regimens, the lack of human trials on this specific peptide form limits confidence in its effectiveness. Benefits are inferred from free leucine studies and preclinical models.
Leucine supplementation (250 mg/kg) attenuated muscle damage markers after eccentric exercise in untrained men.
BCAAs, including leucine, support hepatocyte function and are used therapeutically in chronic liver disease to correct amino acid imbalances.
Systematic review found 90–140 mg/day leucine improved metabolic markers in diet-induced obese rodent models when given early in disease progression.
Leu-Ile-Lys tripeptide reduced oxidative stress and γ-glutamyltransferase activity in a rat model of oxalate nephrolithiasis.
Leucine supplementation did not prevent weight gain or improve glycemic regulation in male rats on a high-fat diet.
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