Home Ingredients Sustamine® (L-Alanyl-L-Glutamine)
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Sustamine® (L-Alanyl-L-Glutamine)

Evidence Level
Moderate
3 Clinical Trials
5 Documented Benefits
3/5 Evidence Score

Sustamine® (Kyowa Hakko) is L-alanyl-L-glutamine, a dipeptide that pairs the amino acids L-alanine and L-glutamine. The dipeptide is far more water-soluble and stable than free glutamine and is absorbed efficiently as an intact peptide, making it a practical way to deliver glutamine in beverages and rehydration products. It is studied mainly for hydration and fluid absorption, gut-barrier support, and endurance/recovery during heat and exercise stress. Sustamine® cross-references the site's L-glutamine entry, but its dipeptide form is its defining advantage. Evidence is promising but built largely on small exercise trials.

Studied Dose Exercise/hydration trials used roughly 1–2 g per 500 mL of fluid during activity, or ~0.05–0.2 g/kg; recovery protocols commonly use ~1–3 g/day.
Active Compound L-Alanyl-L-glutamine dipeptide — Sustamine® by Kyowa Hakko; a highly soluble, stable glutamine carrier absorbed intact via peptide transport.

Benefits

Enhanced Hydration and Fluid Absorption

When added to fluids, Sustamine® can support fluid and electrolyte uptake during exercise and heat stress. Controlled trials suggest it helps maintain hydration status and performance better than water alone during dehydrating exercise.

Supported by Trial 1, Trial 2

Stable, Soluble Glutamine Delivery

Free glutamine is poorly soluble and unstable in solution. The L-alanyl-L-glutamine dipeptide is highly soluble and stable, and is absorbed intact, providing a more practical and bioavailable way to deliver glutamine than free glutamine powder.

Supported by Trial 1, Trial 2

Gut-Barrier Support

Glutamine is a primary fuel for intestinal cells and helps maintain the gut lining and tight-junction integrity. Delivered as a stable dipeptide, Sustamine® may support gut-barrier function, especially under the stress of intense or prolonged exercise.

Supported by Trial 1, Trial 2

Endurance and Time-to-Exhaustion

In endurance settings, adding L-alanyl-L-glutamine to a rehydration drink may help extend time to exhaustion and maintain performance during prolonged effort, particularly when fluid losses are significant.

Supported by Trial 3, Trial 1

Exercise Recovery Support

By supplying glutamine efficiently, Sustamine® may support recovery processes and help maintain skill performance and reaction time during fatiguing, dehydrating activity. Effects are most evident under hydration/heat stress.

Supported by Trial 2, Trial 1

Mechanism of action

1

Intact Dipeptide Absorption (PepT1)

L-alanyl-L-glutamine is absorbed predominantly as an intact dipeptide via intestinal peptide transport rather than requiring free-amino-acid uptake, giving near-complete glutamine bioavailability and rapid delivery.

2

Enhanced Solubility and Stability

The dipeptide is roughly an order of magnitude more soluble than free glutamine and resists the cyclization/hydrolysis that degrades glutamine in solution, allowing stable formulation in beverages and rehydration fluids.

3

Intestinal Fuel and Tight-Junction Support

Glutamine is a key energy substrate for enterocytes and supports expression of tight-junction proteins (occludin, claudins), helping maintain intestinal barrier integrity and water/electrolyte co-transport.

4

Fluid and Electrolyte Co-Transport

Amino-acid and peptide uptake is coupled to sodium and water transport across the gut, a mechanism that helps explain improved fluid absorption when the dipeptide is added to electrolyte beverages.

Clinical trials

1
L-Alanyl-L-Glutamine During Hydration Stress

Randomized study examining acute L-alanyl-L-glutamine ingestion in fluid versus water during exhaustive endurance exercise with and without dehydration in physically active men.

Physically active men; endurance exercise with hydration stress.

Adding the dipeptide to fluid helped maintain performance and supported fluid regulation during dehydrating endurance exercise compared with water alone, supporting hydration and endurance benefits.

2
Dipeptide and Basketball Performance

Trial of L-alanyl-L-glutamine added to water at low and high doses versus water only across simulated competitive basketball games with controlled rehydration.

NCAA Division I women basketball players.

Rehydration with the dipeptide helped maintain basketball shooting skill performance and visual reaction time to a greater extent than water only, indicating performance maintenance under fluid stress.

3
Dipeptide and One-Hour Run Performance

Crossover trial of L-alanyl-L-glutamine with a sports drink versus sports drink alone on time to exhaustion and physiological markers during prolonged endurance running in trained men.

Twelve endurance-trained men.

Ingesting the dipeptide with a sports drink was associated with improved time to exhaustion during prolonged running versus the drink alone, consistent with enhanced fluid regulation and endurance support.

Side effects and drug interactions

Common Potential side effects

Generally well tolerated in exercise and clinical studies.
Mild GI discomfort possible at higher single doses.
No significant adverse effects reported at studied doses.
People with kidney or liver disease should consult a clinician before high glutamine intake.
Limited specific safety data in pregnancy and lactation.

Important Drug interactions

Anticonvulsants — glutamine is a glutamate precursor; theoretical interaction, use caution in seizure disorders.
Chemotherapy agents — discuss glutamine use with an oncologist before combining.
Lactulose or hepatic-encephalopathy therapy — high glutamine/ammonia load may interfere; use caution in liver disease.
Generally minimal interactions with common medications at typical doses.

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Frequently asked questions about Sustamine® (L-Alanyl-L-Glutamine)

What is the recommended dosage of Sustamine® (L-Alanyl-L-Glutamine)?

The clinically studied dose for Sustamine® (L-Alanyl-L-Glutamine) is Exercise/hydration trials used roughly 1–2 g per 500 mL of fluid during activity, or ~0.05–0.2 g/kg; recovery protocols commonly use ~1–3 g/day.. Always follow product labeling and consult a healthcare provider for personalized dosing recommendations.

What is Sustamine® (L-Alanyl-L-Glutamine) used for?

Sustamine® (L-Alanyl-L-Glutamine) is studied for enhanced hydration and fluid absorption, stable, soluble glutamine delivery, gut-barrier support. When added to fluids, Sustamine® can support fluid and electrolyte uptake during exercise and heat stress. Controlled trials suggest it helps maintain hydration status and performance better than water alone during dehydrating exercise.

Are there side effects from taking Sustamine® (L-Alanyl-L-Glutamine)?

Reported potential side effects may include: Generally well tolerated in exercise and clinical studies. Mild GI discomfort possible at higher single doses. Always consult a healthcare provider before starting any new supplement, especially if you have underlying conditions or take medications.

Does Sustamine® (L-Alanyl-L-Glutamine) interact with medications?

Known drug interactions may include: Anticonvulsants — glutamine is a glutamate precursor; theoretical interaction, use caution in seizure disorders. Chemotherapy agents — discuss glutamine use with an oncologist before combining. Consult a pharmacist or healthcare provider if you take prescription medications.

Is Sustamine® (L-Alanyl-L-Glutamine) good for athletic performance?

Yes, Sustamine® (L-Alanyl-L-Glutamine) is researched for Athletic Performance support. When added to fluids, Sustamine® can support fluid and electrolyte uptake during exercise and heat stress. Controlled trials suggest it helps maintain hydration status and performance better than water alone during dehydrating exercise.

References(4 citations)

Evidence ratings on NutraSmarts are based on the totality of human clinical research, with emphasis on randomized controlled trials, meta-analyses, and systematic reviews. The references below directly support claims made throughout this page.

  1. Hoffman JR, Ratamess NA, Kang J, Rashti SL, Kelly N, Gonzalez AM, Stec M, Anderson S, Bailey BL, Yamamoto LM, Hom LL, Kupchak BR, Faigenbaum AD, Maresh CM. Examination of the efficacy of acute L-alanyl-L-glutamine ingestion during hydration stress in endurance exercise. J Int Soc Sports Nutr. 2010;7:8. doi: 10.1186/1550-2783-7-8.PubMedUsed to support: Backs the hydration and endurance benefits: L-alanyl-L-glutamine in fluid helped maintain performance and fluid regulation during dehydrating endurance exercise.
  2. Hoffman JR, Williams DR, Emerson NS, Hoffman MW, Wells AJ, McVeigh DM, McCormack WP, Mangine GT, Gonzalez AM, Fragala MS. L-alanyl-L-glutamine ingestion maintains performance during a competitive basketball game. J Int Soc Sports Nutr. 2012;9(1):4. doi: 10.1186/1550-2783-9-4.PubMedUsed to support: Backs the performance-maintenance benefit: dipeptide rehydration preserved basketball shooting skill and visual reaction time better than water alone.
  3. McCormack WP, Hoffman JR, Pruna GJ, Jajtner AR, Townsend JR, Stout JR, Fragala MS, Fukuda DH. Effects of L-alanyl-L-glutamine ingestion on one-hour run performance. J Am Coll Nutr. 2015;34(6):488-96. doi: 10.1080/07315724.2015.1009193.PubMedUsed to support: Backs the endurance/time-to-exhaustion benefit: dipeptide with a sports drink improved prolonged run performance versus the drink alone.
  4. Kim MH, Kim H. The roles of glutamine in the intestine and its implication in intestinal diseases. Int J Mol Sci. 2017;18(5):1051. doi: 10.3390/ijms18051051.PubMedUsed to support: Supports the gut-barrier mechanism: glutamine is a primary enterocyte fuel and supports tight-junction integrity and intestinal barrier function.