The third branched-chain amino acid, and the one with the least distinctive supplemental profile. Essential in the diet, but with no meaningful case for taking it in isolation.
Typical dose
1.0–5.0 g per day
With protein feedings, if used
What it is
L-valine is an essential amino acid and one of the three branched-chain amino acids. It is present in all complete proteins, with good amounts in meat, dairy, eggs, soy, legumes and grains.
In a standard 2:1:1 BCAA product it occupies the second 1, so a 5 g serving supplies around 1.25 g.
Unlike leucine, which signals protein synthesis, and isoleucine, which affects glucose uptake, valine has no distinctive supplemental role. It is included in BCAA products for completeness rather than for any specific action, and it is the amino acid on this list with the weakest case for individual attention.
How it works
Valine functions as a building block for protein synthesis and, like the other branched-chain amino acids, is metabolised in skeletal muscle rather than the liver, where it can serve as a fuel substrate during prolonged exercise.
It participates in nitrogen transport between tissues and can be converted to intermediates that feed the citric acid cycle, contributing to energy production.
Like its companions, it competes with tryptophan for transport across the blood-brain barrier, which forms part of the central fatigue rationale sometimes offered for BCAAs during endurance exercise.
What the evidence shows
There is no meaningful body of research supporting isolated valine supplementation for muscle, performance or recovery. It is almost never studied alone.
Its relevance in the literature is as part of the complete essential amino acid profile, where its absence would limit protein synthesis just as any other missing essential would.
Deficiency is not a practical concern for anyone eating adequate protein. Being candid: this entry exists for completeness of the amino acid set rather than because valine warrants a purchasing decision of its own.
Dosing
Valine is not typically sold alone. Within a 2:1:1 BCAA product, a 5-10 g serving supplies 1.25-2.5 g. Within a complete EAA product it appears in proportion to the other essentials.
Ordinary dietary protein supplies valine comfortably. A 25 g whey serving delivers well over a gram.
If you are considering individual amino acids, valine is not where to start. A complete protein source or an EAA product covers it as a matter of course, and does so alongside everything else required to actually build muscle protein.
At a glance
Common forms
Within BCAA blends (2:1:1), Within EAA blends, L-valine powder
Half-life / duration
Plasma peak within 30-60 minutes
Timing
With protein feedings, if used
Competition status
Permitted — not on the WADA Prohibited List
Category
Muscle & Recovery
Safety and side effects
Valine is an ordinary dietary component and well tolerated. Digestive discomfort at high isolated doses is the main reported effect, and unflavoured powder is notably bitter.
Large isolated doses of any branched-chain amino acid compete with tryptophan and tyrosine for brain transport, which is a reason to prefer balanced products over single amino acids.
Anyone who has been advised to restrict specific amino acids in their diet should avoid it entirely.
Who should avoid it
Avoid if you have been advised to restrict specific amino acids in your diet. Speak to your doctor before use if you take regular medication or are under medical care. Not established for use in pregnancy or breastfeeding at supplemental doses.
This entry is provided for information only. Food supplements should not be used as a substitute for a varied and balanced diet and a healthy lifestyle. Consult a qualified healthcare professional before use if you are pregnant, breastfeeding, taking medication or under medical supervision.
