Valine

amino acid

What is it

Valine is an essential branched-chain amino acid (BCAA) that the body cannot synthesize. It contributes to protein synthesis, muscle energy metabolism, nitrogen balance, and the synthesis of glutamate and other amino acids in muscle.

How it works

Like the other BCAAs (leucine and isoleucine), valine is absorbed in the small intestine and metabolized primarily in skeletal muscle. Inside muscle, valine is either incorporated into proteins or oxidized for energy through the branched-chain alpha-ketoacid dehydrogenase complex (BCKDC). During prolonged exercise, BCAAs serve as accessible fuel as muscle glycogen depletes. Valine contributes to maintaining a positive nitrogen balance and supports the synthesis of glutamate, alanine, and glutamine in muscle, helping shuttle nitrogen between tissues. While valine is less potent than leucine in activating mTOR for muscle protein synthesis, it is required alongside leucine for complete protein synthesis. Valine is the third member of the BCAA family and is essential for normal growth, tissue repair, and energy metabolism. Severe deficiency causes growth impairment and neurological issues.

Evidence for 5 uses

AI-assisted evidence assessment — talk to your doctor before relying on any single supplement.

Muscle protein synthesis (as part of complete protein / BCAA)

Grade B

Good evidence

Valine is required for normal protein synthesis, though it is less potent than leucine at directly activating mTOR. Its main contribution is structural and as an energy substrate during exercise.

Nitrogen balance / liver disease

Grade B

Good evidence

BCAA blends including valine are used in hepatic encephalopathy management to improve nitrogen balance, mental status, and nutritional state in cirrhosis.

Exercise recovery (BCAA blend)

Grade C

Moderate evidence

BCAA supplementation including valine may modestly reduce exercise-induced muscle damage and soreness, particularly with suboptimal baseline protein intake.

Muscle energy during prolonged exercise

Grade C

Moderate evidence

Valine is oxidized as fuel in muscle, contributing to BCAA-based energy production during endurance exercise. Effect on actual performance is modest.

Catabolic illness / trauma support

Grade C

Moderate evidence

BCAA-enriched nutrition has been studied in trauma and burn patients to support nitrogen balance and muscle preservation, with modest benefit in specific clinical scenarios.

3 commercial forms

L-valine (free form)

Rapidly absorbed; rarely sold standalone.

Used in formulations where individual amino acids are dosed.

Instantized L-valine

Easier mixing in liquids; same biological activity.

Common in athletic supplements for convenience.

BCAA blend (with leucine and isoleucine)

Standard 2:1:1 ratio.

Most common way to consume supplemental valine.

Dosage

The RDA for valine is 24 mg/kg/day (about 1,680 mg for a 70 kg adult). Typical BCAA supplements provide valine as part of a 2:1:1 leucine:isoleucine:valine blend, supplying 1-2 g of valine per serving. Standalone valine is uncommon. No formal UL exists; doses up to several grams per day are well-tolerated.

When and how to take it

Valine is typically consumed as part of a complete BCAA blend with meals or around workouts. Pre- or intra-workout BCAA dosing (5-10 g of total BCAAs providing 1-2 g valine) is common. Steady distribution across the day supports protein synthesis and recovery.

Food sources

FoodAmount%DV
Chicken breast (3 oz, cooked)1,400 mg—
Beef (3 oz, cooked)1,200 mg—
Tuna (3 oz, cooked)1,300 mg—
Salmon (3 oz, cooked)1,100 mg—
Eggs (1 large)410 mg—
Cottage cheese (1/2 cup)950 mg—
Whey protein (1 scoop, ~25g)1,400-1,700 mg—
Lentils (1 cup, cooked)1,000 mg—

Safety

Valine at typical supplement doses is well-tolerated. Very high doses may cause skin tingling, hallucinations, or impair metabolism of other BCAAs. Long-term high-dose safety is not well-characterized. Avoid in maple syrup urine disease.

Who should be cautious

Avoid in maple syrup urine disease. Caution in advanced liver or kidney disease. Pregnant and lactating women should stay within dietary amounts unless directed by a clinician. Children should not take high-dose supplements without medical guidance.

Interactions

Shares transport with leucine and isoleucine; high single-BCAA doses can affect the others. May reduce levodopa absorption. Few significant drug interactions otherwise.

Frequently asked questions

Do I need valine supplements?⌄

Almost certainly not standalone. Complete-protein meals provide ample valine. BCAA blends include it for convenience around workouts.

How is valine different from leucine and isoleucine?⌄

All three are BCAAs metabolized in muscle. Leucine is the strongest mTOR activator. Isoleucine has unique effects on glucose uptake. Valine contributes to protein synthesis and energy substrate during exercise.

Is the 2:1:1 BCAA ratio important?⌄

It approximates the relative needs and the ratios found in many high-quality proteins. Most BCAA products use this ratio. Variations (e.g., 4:1:1, 8:1:1) emphasize leucine more but offer little practical advantage for most users.

Can valine alone help with anything?⌄

Standalone valine is rarely used. Its effects on protein synthesis are weaker than leucine; it works best as part of a complete protein or BCAA mix.

Is valine safe long-term?⌄

At dietary and typical supplement levels, yes. Very high doses can cause skin tingling and other side effects. Avoid in maple syrup urine disease.

References

  • Valine - Wikidata — Wikidata link

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Set up dose reminders, check interactions, and join the community in the Pilora iPhone app.

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Disclaimer: These statements have not been evaluated by the FDA. This page is educational, not a substitute for personalized medical advice. Evidence grades are AI-assisted assessments — talk to your doctor before starting any new supplement, especially if you're pregnant, breastfeeding, on medications, or managing a chronic condition.