All About Beta-Alanine

What is beta-alanine?

Beta-alanine, also known as 3-aminopropanoic acid, is a non-essential amino acid. It’s found naturally in the body, which can synthesize beta-alanine from the breakdown of pyrimidine nucleotides. We can also get beta-alanine from our diets via carnosine, and to a lesser extent from anserine and balenine.

Carnosine is a dipeptide –- a molecule made up of two amino acids bonded together — composed of beta-alanine and histidine. These dipeptides are found in chicken, beef, fish, and pork. (Think of the word “carnivore” to help you remember where to get carnosine.) In humans, carnosine seems to be concentrated in tissues that have a high energy demand, such as muscle and brain.

Beta-alanine structure

Why is beta-alanine important?

During exercise (especially at high intensity), the formation of energy (ATP) and rise in hydrogen (H+) ions occurs. The rise in H+ ions is mainly due to lactic acid production, which lowers the body’s pH (i.e. creating a more acidic state). As the acidity rises, it’s harder to contract the muscle, and fatigue can result. Thus, if the body can combat the acidity, it can keep working harder.

The body’s first line of defense against this acidic pH is inside the muscle cell. Carnosine is able to buffer H+ ions in muscle cells. This buffering can neutralize lactic acid and simultaneously increase ATP stores.

Carnosine also acts as an anti-glycation agent and antioxidant. Moreover, carnosine appears to help activate the enzymes responsible for muscle contraction.

Because carnosine is so important, beta-alanine is also important. Without enough beta-alanine the body can’t make carnosine effectively, which means that these essential cellular functions are impeded. Since most people usually have enough histidine (the other part of carnosine), and since consuming histidine by itself seems to have little to no impact on cellular carnosine levels, the limiting factor in carnosine synthesis is beta-alanine.

What you should know

Beta-alanine can enter a muscle cell and increase carnosine levels. In this case, beta-alanine is more like a means to an end –- carnosine.

If we increase carnosine levels in cells through beta-alanine supplementation, we can enhance intracellular buffering and reduce acid accumulation during exercise. Therefore, in people doing exercise that causes significant alterations in cellular pH and high amounts of lactate in the blood, beta-alanine may improve performance and therefore lead to greater training adaptations. Along with buffering lactic acid, beta-alanine supplementation may help with healing, muscle recovery, and muscle contraction.

Since the idea of beta-alanine supplementation is to elevate muscle carnosine levels, why not just supplement with carnosine? Well, carnosine isn’t absorbed very well in humans. When it’s consumed, it will actually be broken down into its respective amino acids (beta-alanine and histidine). When those amino acids enter a muscle cell, they will join to form carnosine again. Thus, someone who supplements with carnosine would really just be using it as a beta-alanine source.

Carnosine is found exclusively in animal tissues. This makes sense as it’s concentrated in muscle and brain tissues. Hence, a diet with minimal animal foods lacks carnosine (similar to creatine). Reports have indicated that carnosine levels in those eating a plant-based diet are diminished. The average daily intake of carnosine from foods is likely in the range of 50 – 250 milligrams. This is only if a diet contains ~4 ounces of beef, pork, fish or chicken.

One month of beta-alanine supplementation (at 4-6 grams per day) can significantly increase muscle carnosine levels. Extending the supplementation protocol over 2 ½ months increases muscle carnosine levels even further. In untrained individuals, beta-alanine supplementation doesn’t seem to be quite as effective at raising muscle levels of carnosine. This is important, as the extent to which carnosine can delay acidosis is relative to its content inside muscle cells.

A recent study found that resistance training for 10 weeks along with beta-alanine supplementation raised muscle levels of carnosine. Yet beta-alanine had no significant influence on strength, force, endurance or body composition.

For extra credit

Past studies have used chicken breast extract as a source of carnosine. But it wasn’t very effective at increasing muscle levels of carnosine.

Creatine may promote strength and power during very brief bouts of exercise (6 reps or less), while beta-alanine may promote strength and power during slightly longer bouts (more than 7 reps).

When individuals supplement with more than 800 mg of beta-alanine at a single dose, they may notice parasthesia (e.g. “pins and needles” or tingling sensations). This is because beta-alanine can bind to and discharge nerve receptors. Onset can be rapid and last for hours. Concurrently using carbohydrates with beta-alanine may blunt the parathesia.

Only after muscle levels of carnosine increase will performance changes be noticed. This can take ~14 days.

Taking beta-alanine along with carbohydrates and during the peri-workout period may allow more of it into the muscle cell.

Carnosine may help those with autism.

Summary and recommendations

In theory, beta-alanine supplementation may help to delay fatigue, increase anaerobic threshold, increase power, increase strength, and increase muscle mass. Still, the data is far from conclusive, with some studies showing a benefit and others showing no improvements.

Beta-alanine may be of use to highly trained athletes whose limiting factor is buffering excessive H+ production. If you’re on a tight budget, you may want to hold off on using beta-alanine until more information becomes available. However, if you like to be a guinea pig and have money to spend, it appears that controlled doses of beta-alanine shouldn’t cause harm.