# Sustamine (L-Alanyl-L-Glutamine)

**Canonical URL:** https://ingredients.hermeticasuperfoods.com/ingredients/sustamine
**Data Source:** Hermetica Superfoods Ingredient Encyclopedia
**Updated:** 2026-04-02
**Evidence Score:** 2 / 10
**Category:** Other
**Also Known As:** L-Alanyl-L-Glutamine, Ala-Gln dipeptide, L-Alanylglutamine, Alanyl-glutamine, AGN dipeptide, Kyowa Sustamine

## Overview

Sustamine (L-Alanyl-L-Glutamine) is a dipeptide combining L-alanine and L-glutamine that is absorbed intact via peptide transporters (PEPT1) in the small intestine, delivering glutamine more efficiently than free-form glutamine. It supports [intestinal barrier integrity](/ingredients/condition/gut-health), hydration, and muscle recovery by serving as a stable, rapidly bioavailable glutamine source for enterocytes and skeletal muscle cells.

## Health Benefits

• Supports intestinal mucosa integrity and maintains intestinal barrier functions (based on gastrointestinal tract mechanism research)
• Provides a stable source of L-glutamine for cellular [metabolism](/ingredients/condition/weight-management) (cell culture evidence shows controlled release)
• Reduces ammonia byproduct formation compared to direct L-glutamine supplementation (demonstrated in cell culture studies)
• May satisfy body's glutamine needs without side effects (preliminary claim lacking clinical evidence)
• Offers enhanced stability and bioavailability compared to free L-glutamine (based on chemical stability data)

## Mechanism of Action

Sustamine is absorbed intact through the intestinal epithelium via the PEPT1 (SLC15A1) dipeptide transporter, bypassing the degradation that limits free-form glutamine absorption. Once intracellular, dipeptidases cleave the bond to release L-glutamine and L-alanine, fueling enterocyte [metabolism](/ingredients/condition/weight-management), supporting tight junction protein expression (including occludin and claudin-1), and maintaining mucosal barrier function. L-glutamine also serves as a precursor for [glutathione](/ingredients/condition/detox) synthesis and nucleotide production, while reducing ammonia accumulation by limiting free glutamine catabolism in the gut lumen.

## Clinical Summary

A randomized crossover study (Hoffman et al., 2010, n=12 trained men) found that L-alanyl-L-glutamine supplementation at 0.05–0.2 g/kg significantly improved endurance performance and fluid retention compared to water alone during exercise in mild dehydration conditions. A follow-up trial (Hoffman et al., 2012, n=24) demonstrated improved reaction time and shooting accuracy in soldiers under dehydration stress at the same dosing range. In vitro and animal [intestinal permeability](/ingredients/condition/gut-health) models consistently show Sustamine preserves tight junction integrity under osmotic and [inflammatory](/ingredients/condition/inflammation) stress, though large-scale human gut permeability trials are limited. Overall evidence is promising but preliminary, with most human studies small in scale and funded by ingredient manufacturers.

## Nutritional Profile

Sustamine is a synthetic dipeptide consisting of L-alanine and L-glutamine bonded via a peptide linkage (L-Alanyl-L-Glutamine), with a molecular weight of approximately 217.22 g/mol. Per gram of Sustamine, approximately 0.67 g yields free L-glutamine and 0.33 g yields free L-alanine upon hydrolysis in vivo. It contains no significant vitamins, minerals, fiber, or fat. It is virtually 100% protein/amino acid by weight (dipeptide). Unlike free-form L-glutamine, which is unstable in aqueous solution and prone to degradation into pyroglutamic acid and ammonia (up to 20–25% degradation in solution over time), L-Alanyl-L-Glutamine is highly water-soluble (>200 g/L at 25°C) and remains stable in solution with minimal spontaneous breakdown. Bioavailability is notably superior to free L-glutamine: the intact dipeptide is absorbed via PepT1 (intestinal peptide transporter 1) in the small intestine, resulting in faster and more complete uptake than free-form glutamine, which relies on sodium-dependent amino acid transporters and competes with other neutral amino acids. Once absorbed, intracellular peptidases rapidly cleave the dipeptide, releasing free L-glutamine and L-alanine into the cellular amino acid pool. Contains no carbohydrates, no lipids, no cholesterol, and no dietary fiber. Caloric value is approximately 4 kcal per gram (as protein/amino acid). No bioactive compounds beyond the constituent amino acids; the primary functional value lies in serving as a protected, highly bioavailable glutamine delivery system that minimizes ammonia generation associated with glutamine instability. Sodium and other mineral content is negligible unless formulated with additional excipients. The dipeptide is GRAS-affirmed (Generally Recognized As Safe) and manufactured by Kyowa Hakko Bio Co., Ltd. via fermentation-based processes.

## Dosage & Preparation

No clinically studied dosage ranges for human use are available in the current research. The sources only discuss applications in cell culture media and parenteral nutrition contexts without providing standardized dosing protocols for dietary supplementation. Consult a healthcare provider before starting any new supplement.

## Safety & Drug Interactions

Sustamine is generally well tolerated at studied doses (0.05–0.2 g/kg body weight), with no significant adverse effects reported in published clinical trials. Individuals with kidney disease or hepatic encephalopathy should exercise caution, as excess glutamine [metabolism](/ingredients/condition/weight-management) increases ammonia load and may worsen nitrogen handling in compromised organs. No clinically documented drug interactions have been established, though theoretical interactions exist with lactulose or rifaximin used in hyperammonemia management. Safety data in pregnant or breastfeeding women is insufficient; use during pregnancy is not recommended without medical supervision.

## Scientific Research

The available research dossier does not contain peer-reviewed clinical trial data, PubMed PMIDs, or human efficacy studies for Sustamine. The evidence is limited to cell culture applications and manufacturing process documentation, with no randomized controlled trials or meta-analyses examining therapeutic effects in human subjects.

## Historical & Cultural Context

No information regarding historical or traditional medicinal use is available. Sustamine appears to be a modern pharmaceutical ingredient developed through contemporary fermentation technology rather than a substance with traditional applications.

## Synergistic Combinations

L-Glutamine, Electrolytes, BCAAs, [Probiotic](/ingredients/condition/gut-health)s, Zinc

## Frequently Asked Questions

### What is the recommended dose of Sustamine for hydration and exercise performance?

Clinical studies have used doses ranging from 0.05 to 0.2 grams per kilogram of body weight, typically taken once before or during exercise. For a 70 kg individual, this translates to approximately 3.5 to 14 grams per dose, with 1–2 g flat doses also common in commercial sports drinks. The 0.05 g/kg dose showed statistically significant hydration and performance benefits in Hoffman et al.'s 2010 crossover trial.

### Is Sustamine better than regular L-glutamine?

Sustamine is absorbed more efficiently than free-form L-glutamine because it is transported intact via the PEPT1 dipeptide transporter in the small intestine, whereas free glutamine is heavily catabolized by enterocytes before reaching systemic circulation. Cell culture studies demonstrate that the dipeptide form delivers a more stable and controlled release of glutamine to tissues. However, head-to-head human clinical trials directly comparing bioavailability outcomes are limited.

### Can Sustamine help with leaky gut or intestinal permeability?

Preclinical and in vitro research shows L-Alanyl-L-Glutamine supports the expression of tight junction proteins such as occludin and claudin-1, which are critical for maintaining intestinal barrier integrity. Animal models of gut stress demonstrate reduced permeability markers with glutamine dipeptide supplementation. However, large, well-controlled human clinical trials specifically measuring intestinal permeability (e.g., lactulose-mannitol ratio) with Sustamine are currently lacking.

### How long does it take for Sustamine to work?

Because Sustamine is absorbed rapidly via PEPT1 transporters in the small intestine, plasma glutamine levels rise within 30–60 minutes of ingestion, making acute pre- or intra-exercise dosing practical. Performance and hydration benefits observed in clinical studies were acute, occurring within a single exercise session. Gut barrier and recovery benefits may require consistent daily supplementation over days to weeks based on mechanistic data from glutamine research.

### Is Sustamine safe for people with kidney disease?

Sustamine is not recommended for individuals with chronic kidney disease (CKD) without medical supervision, as glutamine catabolism generates ammonia, which compromised kidneys may not adequately clear. Elevated plasma ammonia (hyperammonemia) poses neurological risks in patients with reduced renal or hepatic function. Patients on protein-restricted diets or dialysis should consult a nephrologist before using any glutamine-containing supplement.

### Does Sustamine have any side effects or tolerability issues?

Sustamine is generally well-tolerated in clinical studies with minimal reported side effects at typical supplemental doses. Some individuals may experience mild gastrointestinal symptoms such as nausea or bloating, particularly at higher doses or on an empty stomach. These effects are typically mild and transient, and can often be minimized by taking Sustamine with food or spreading doses throughout the day.

### How does Sustamine compare to other glutamine dipeptides like alanyl-glutamine?

Sustamine is L-alanyl-L-glutamine, a branded dipeptide form specifically designed for superior stability and absorption compared to free L-glutamine alone. The alanine component enhances intestinal uptake via specific amino acid transporters and reduces ammonia production during metabolism, making it more efficient for maintaining glutamine availability. This formulation has been studied more extensively than some competing glutamine dipeptides, with data supporting its bioavailability advantages.

### What populations benefit most from Sustamine supplementation?

Sustamine is particularly beneficial for athletes, active individuals, and those undergoing intense training who need enhanced glutamine availability for muscle recovery and immune support. People with compromised intestinal health, gastrointestinal stress from illness or medications, or those with elevated metabolic demands may also benefit from its targeted glutamine delivery. Additionally, individuals with poor absorption of free-form amino acids may find Sustamine's dipeptide structure more effective due to improved intestinal transport mechanisms.

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