What is Valine?
L-valine is an essential amino acid. The human body cannot manufacture essential amino acids, so they have to come from food or supplement sources. Valine is also known as a branch chain amino acid (BCAA). Leucine and isoleucine are two additional BCAAs that it works with. Valine is a BCAA that is used as a muscle-building supplement. It’s beneficial for repairing damaged muscle, decreasing muscle fatigue, improving performance and endurance, and helping to boost the immune system.
Benefits of Valine
The main benefit that valine possesses is the ability to help stimulate protein synthesis and muscle growth. Valine’s ability to stimulate muscle growth and repair is not as strong compared to isoleucine or leucine. Because of this weaker muscle-building effect, valine is rarely taken on its own and is combined with the other BCAA for maximum muscle growth stimulation. Valine stimulates protein synthesis and ultimately muscle growth by activating mTOR.  mTor, which stands for the Mammalian target of rapamycin. mTOR mediates skeletal muscles growth by controlling the muscle’s anabolic and catabolic environment.  Even though valine can stimulate mTOR, it does it to a much lesser extent than leucine or even isoleucine. 
Increased performance and recovery
Like the other two BCAA, Valine can help improve performance and speed recovery from training and workouts. In one study done using rats in 2018, valine was administered before exercise to see how it would affect liver glycogen and blood glucose levels post-exercise. The researchers found that the test subjects who consumed valine had maintained their liver glycogen and blood glucose levels even after exercise.  This study shows that valine has a glycogen and glucose sparing effect. If your stored glycogen is intact after training, your body does not have to expend energy trying to replenish it, which can help the body recover quicker. This energy sparing effect can help performance and training by maintaining energy reserves of glycogen to be used later in the training session.
Unlike leucine or isoleucine, valine does not increase glucose uptake into the muscle cells. Instead, it seems almost to do the opposite. Research has shown that valine can increase the glucose level in the blood.  The increased blood glucose might not be bad, depending on the context you are using valine for. If you are an athlete who needs an elevated or steady supply of glucose in the bloodstream to fuel your intense workouts or training, then this would be a significant benefit to your training.
Valine supplementation can improve and stimulate dendritic cell and monocyte interaction and increase interleukin 12 (IL-12) secretion.  Dendritic cells are key immune cells as they take the invading antigen material and place it on the outside of the cell, presenting it to the killer T cells of the immune system. IL-12 is a cytokine produced by the dendritic cells, and it is the main regulator of T cell activity and how they respond to antigens.
research done with hepatitis C patients has demonstrated that valine has antiviral properties. Test subjects were titrated up from 3g of valine up to 12g of valine daily. At the end of the study, researchers discovered that valine could greatly decrease the level of circulating hep C virus in the blood. They also found that levels of Alpha-fetoprotein, a diagnostic blood test for Hep C, were significantly decreased. 
Side Effects of Valine
The above side effects are rare because most healthy users will not develop hyperammonemia, as the body will excrete the ammonia. So for most people, the common side effects are mostly gastrointestinal in nature and mild. Below are the most common side effects.
The most efficacious dosage for valine supplementation is between 3 to 12 grams. More research is needed to determine the optimal valine dosage for performance and muscle growth. Still, this is the best dosage range that showed the lowest chance of producing side effects from the studies currently available. Each user will have to determine what dose is optimal for them and their training goals. Also, users need to be cognisant of gastrointestinal issues and start with a lower dose and work their way up to a higher dose if desired.
When is the best time to take valine?
Like the other branched-chain amino acids, valine should be taken with food. Valine is best taken before training or working out, as this will help with performance during the training session. Post-workout supplementation can help speed recovery and enhance muscle growth and repair. Some users will also supplement intra-workout. It is best to take valine throughout the day to keep the amino acid levels stable and have a steady supply of the amino acid present for your body to utilize.
Dietary Sources of Valine
- Red meat
- Sunflower seeds
- Flax seeds
- Chia seeds
- Navy beans
- Kidney beans
- Brown rice
Summary of Valine
Valine is a very interesting amino acid and has some interesting benefits that could help athletes and bodybuilders.
- Regulation of protein synthesis in porcine mammary epithelial cells by l-valine | SpringerLink
- mTOR as a Key Regulator in Maintaining Skeletal Muscle Mass (nih.gov)
- Regulation of amino acid-sensitive TOR signaling by leucine analogues in adipocytes – PubMed (nih.gov)
- Acute supplementation of valine reduces fatigue during swimming exercise in rats – PubMed (nih.gov)
- Isoleucine, a potent plasma glucose-lowering amino acid, stimulates glucose uptake in C2C12 myotubes – PubMed (nih.gov)
- Extracellular branched-chain amino acids, especially valine, regulate maturation and function of monocyte-derived dendritic cells – PubMed (nih.gov)
- Valine, a branched-chain amino Acid, reduced HCV viral load and led to eradication of HCV by interferon therapy in a decompensated cirrhotic patient – PubMed (nih.gov)
- Dynamics of serum α‑fetoprotein in viral hepatitis C without hepatocellular carcinoma (spandidos-publications.com)
- Hyperammonemia Due to Valproic Acid in the Psychiatric Setting | American Journal of Psychiatry (psychiatryonline.org)
This article and the information contained within it are not intended to be taken as health or medical advice. Always talk with your physician prior to taking any supplements.