Essential Amino Acids

Isoleucine is an essential amino acid. This means the body cannot produce it, therefore you need to include it in your diet. This amino acid has many roles within the human body. It is best known for its ability to support blood clotting at wound sites and assisting with muscle tissue repair. L-isoleucine can also help to boost energy levels and improve stamina.

Consequently, this is a widely used amino acid supplement for body builders and endurance athletes1. Not only does it provide an added energy boost, it also helps the body to repair faster following periods of strenuous physical activity2

Uses of isoleucine

Isoleucine is one of three specialised amino acids known as branched-chain amino acids (BCAAs). This group also includes leucine and valine. Branched-chain amino acids assist with muscle recovery following exercise.

The body breaks down isoleucine within the muscle tissue to generate energy. Additionally, this amino acid helps to regulate blood sugar levels to stabilise energy levels. Isoleucine significantly increases the body’s ability to utilise glucose during exercise. However, it does not promote the synthesis of glycogen.

Natural sources of isoleucine

High protein foods are typically rich in this essential amino acid. Meat, fish, eggs, nuts, seeds, and pulses are all good sources of isoleucine. However if you have a low-protein diet or exercise a lot, you might need to consider taking supplements. Many dietary supplements include this amino acid.

However, it is important not to take isoleucine alone and it should always be paired with valine and leucine for the best results. The recommended dosage ratio is 1 milligram of isoleucine together with 1 milligram of  valine and 2 milligrams of leucine.

Scientists think that this is the best ratio for optimal absorption. There are many supplements that contain all BCAAs in the correct ratios for convenience.
Prior to taking any supplement it is important to first consult with a medical practitioner. For people with impaired kidney or liver function isoleucine may worsen these conditions.

RDA 35 mg/kg        One serving of Spirulina 1,400 mg


Leucine is one of the three branched chain amino acids and sometimes referred to as the 'main' amino acid due to the most popular benefit of BCAAs (muscle building) being mostly due to leucine. Leucine is an activator of the protein known as mTOR, which then induces muscle protein synthesis via S6K; the other two BCAAs may also activate mTOR, but are much weaker than leucine in doing so (and as such, 5g of leucine will be more effective than 5g mixed BCAAs). The leucine metabolite, HMB, is also weaker than leucine at inducing muscle protein synthesis despite being more effective at preserving lean mass from breakdown.

Leucine is a tad different from the other two BCAAs isoleucine and valine as leucine seems to have a fair bit of testing on the amino acid in isolation rather than in a BCAA mixture, whereas the other two BCAAs are not as well studied.
The studies assessing leucine mostly look at muscle protein synthesis when additional leucine is added to the diet or to a test meal, and it appears that leucine is able to reliably increase muscle protein synthesis after test meals. Whether this results in more lean mass over a period of time is somewhat less reliable though, and leucine appears to be more effective at promoting gains in muscle in people with lower dietary protein intake and in the elderly (who tend to have impaired muscle protein synthesis in response to the diet).
The interactions of leucine on glucose are not clear, to be honest. Leucine possesses both blood sugar reducing properties (can release insulin from the pancreas, can directly stimulate glucose uptake into a cell without insulin) but also the opposite (via stimulating S6K, it can inhibit insulin-stimulated glucose uptake). In a cell culture, leucine stimulates glucose uptake for up to 45 minutes and then hinders itself while in living systems acute doses of leucine do not appear to do anything remarkable (some limited evidence that leucine can be rehabilitative in diabetes, but this is preliminary). Isoleucine is a more potent hypoglycemic agent, but to less inhibition of its own actions.

RDA  29mg/kg        One serving of Spirulina 2,160 mg

Lysine is a building block for protein. It’s an essential amino acid because your body cannot make it, so you need to obtain it from food.

It’s important for normal growth and muscle turnover and used to form carnitine, a substance found in most cells of your body. What’s more, it helps transport fats across your cells to be burned for energy.

L-lysine is the form of lysine your body can utilize. It’s naturally found in food and is the type used in supplements.

Cold sores or fever blisters are symptoms of an infection, often appearing on the lip or the corners of your mouth.They appear as fluid-filled blisters that can cause discomforts, such as tingling, pain and burning. Plus, they may make you feel self-conscious about your appearance. Cold sores are caused by the herpes simplex virus type 1 (HSV-1), which can hide in your spine. In times of stress or if your immune system is weakened, HSV-1 can trigger the development of a cold sore (1Trusted Source).  Lysine supplements may help prevent HSV-1 from replicating and reduce the duration of a cold sore.

One study found that a daily supplement of 1,000 mg of lysine resulted in fewer cold sores in 26 people who were prone to recurrent cold sores.

Interestingly, the study observed reduced cold sore breakouts when a person’s blood lysine measure was kept above 165 nmol/l. When blood levels dropped below this level, cold sore breakouts increased

Another study in 30 people found that applying a cream with lysine, herbs, vitamins and zinc cleared cold sores in 40% of people by day three and in 87% by day six.

Though this study is promising, it did not state the amount of lysine or other ingredients used in the cream Furthermore, not all studies show that lysine is effective in reducing cold sore occurrence or duration.

RDA of 38 mg/kg of body weight per day for adults over 19 years old. ... The RDA of lysine is 89 mg/kg/day for infants 7 to 12 months old, 58 mg/kg/day for children 1 to 3 years old, and 40-46 mg/kg/day for children 4 to 18 years old.

RDA  See above        One serving of Spirulina 1,160 mg

Methionine is an amino acid that produces several important molecules in your body. These molecules are essential for the proper functioning of your cells.

Because of the important molecules it produces, some recommend increasing methionine intake. However, others recommend limiting it due to possible negative side effects.

Methionine is an essential amino acid found in many proteins, including the proteins in foods and those found in the tissues and organs of your body.

In addition to being a building block for proteins, it has several other unique features.
One of these is its ability to be converted into important sulfur-containing molecules Sulfur-containing molecules have a variety of functions, including the protection of your tissues, modifying your DNA and maintaining proper functioning of your cells (2Trusted Source, 3).

These important molecules must be made from amino acids that contain sulfur. Of the amino acids used to make proteins in the body, only methionine and cysteine contain sulfur.

Although your body can produce the amino acid cysteine on its own, methionine must come from your diet (4).

Additionally, methionine plays a critical role in starting the process of making new proteins inside your cells, something that is continuously occurring as older proteins break down (1Trusted Source).

For example, this amino acid starts the process of producing new proteins in your muscles after an exercise session that damages them (1Trusted Source, 5Trusted Source).

Overall, methionine is directly or indirectly involved in many important processes in the body because of the molecules it can become.

RDA  19 mg/kg        One serving of Spirulina 560  mg

Phenylalanine comes in several forms as a supplement:
  • L-phenylalanine is an essential amino acid. It's also found in protein in the foods we eat.
  • D-phenylalanine
  • DL-phenylalanine, which contains both the D- and L-form
Phenylalanine is not a widely accepted treatment for any condition.

But people have tried to treat a number of conditions with phenylalanine,including:
Some research, mainly from the 1970s and 1980s, offers some support for using it for depression. Several studies also showed that L-phenylalanine plus ultraviolet A light may be helpful for people with vitiligo.

There is less evidence to support its use for other conditions.

Optimal doses of phenylalanine have not been set for any condition. Quality and active ingredients in supplements may vary widely from maker to maker. This makes it difficult to set a standard dose. However, commonly used dosages, depending on the condition, range from 150 mg to 5,000 mg daily.

Phenylalanine is found in many foods, including:
  • Meat
  • Eggs
  • Fish
  • Cheese
  • Products containing aspartame
RDA  See Above        One serving of Spirulina 1,120  mg

Threonine is an essential amino acid. Amino acids are the building blocks the body uses to make proteins. The "essential" amino acids are those that cannot be made by the body and must be obtained from the diet.

People use threonine for conditions such as a muscle control disorder marked by involuntary movements and muscle tightness (spasticity), multiple sclerosis (MS), inherited disorders marked by weakness and stiffness in the legs (familial spastic paraparesis or FSP), and Lou Gehrig's disease (amyotrophic lateral sclerosis or ALS), but there is no good scientific evidence to support these uses.

Threonine is changed in the body to a chemical called glycine. Glycine works in the brain to reduce constant and unwanted muscle contractions (spasticity).

RDA  20 mg/kg        One serving of Spirulina 1,280  mg

This amino acid aids preventing the breakdown of muscle, because it supplies the muscles with an extra glucose responsible for the energy production during physical activity. Valine is also a precursor in the penicillin biosynthetic pathway and is known for inhibiting the transport of Tryptophan across the blood-brain barrier.

In other words, Valine is an essential amino acid important for smooth nervous system and cognitive functioning. Valine is one of the three branched-chain amino acids, along with Leucine and Isoleucine. This amino acid cannot be produced by your body and must be obtained through food or through supplements. Valine is important for everyday body functions and for maintaining muscles, as well as for the regulation of the immune system. This particular amino acid is not processed by the liver, but is taken up by muscles. You can obtain it through kidney beans, leafy vegetables, poultry and milk.

Valine provides numerous benefits like improvement in insomnia and nervousness. Besides, it is also proved to help alleviate disorders of the muscles, and to be an effective appetite suppressant. This amino acid also greatly improves the regulation of the immune system, but probably the greatest benefits of Valine are experienced by athletes performing long-distance sports and bodybuilding, because this amino acid is important for the muscle tissue recovery and for the muscle metabolism, while increasing exercise endurance.

Bodybuilders usually use Valine together with Isoleucine and Leucine to promote muscle growth and to supply them with an energy. Besides, this amino acid helps them recover tissues damaged during physical activity. Athletes commonly know that Valine is vital for the muscle metabolism and the growth of muscle tissue as it assists in maintaining the proper amount of nitrogen in the body.

RDA  19 mg/kg        One serving of Spirulina 1,280  mg