Amino acids offer many benefits besides their well-known roles as the backbones of proteins. Two amino acids, L-glutamine and L-lysine, are particularly versatile.

They provide multiple anti-aging effects. Together they now occupy a top spot among the most revered of the healthy aging supplements.

Note that the biologically active amino acids are designated with an “L” in front of their names. This designation indicates one of two possible forms of a molecule. The “L” form is the one that occurs in enzymes and other proteins in your body.


The wide variety of L-glutamine benefits come from its involvement in more metabolic processes than any other amino acid.

This is why it is the most abundant amino acid in your bloodstream.

Most of the L-glutamine in your body occurs in muscle tissue. It is also abundant in structural proteins that make up skin, bone, and internal organs.

Your ability to produce L-glutamine typically decreases as you age. One of the consequences of the age-related loss of L-glutamine from muscle is a drop in muscle strength.

Diminished levels of this crucial amino acid also drive the reduction of skin firmness and elasticity that is associated with aging.

Additionally, L-glutamine plays a crucial role in regenerating glutathione in the gut (1998).

Glutathione is one of the most important antioxidants that your body makes.

It is a key factor in your ability to reduce chronic inflammation as you age.

L-glutamine depletion also characterizes many disorders of the gastrointestinal tract.

Such disorders lie behind age-related loss of immunity to many infections, since the majority of immune system cells are formed in the small intestine.

Suppression of the immune system in patients after surgery or during cancer chemotherapy is particularly problematic due to loss of L-glutamine.

Supplementation with L-glutamine is known to ease these medical issues (1999).

In addition, reviews of several clinical trials (2001) show the importance of L-glutamine supplementation for alleviating a number of the diseases of aging.

Overall, based on its many roles in healthy aging, L-glutamine is considered to be like an internal fountain of youth.

However, you must have enough of it in the right places for it to work. Fortunately, you can overcome the normal age-related loss of L-glutamine through supplementation.

Although L-glutamine is widely available from many sources, be sure to take only the best L-glutamine supplement that you can find.

Make sure that it carries the USDA Organic certification label.

What about L-glutamine side effects? It is associated with very few. A risk assessment of L-glutamine supplementation shows that it is safe in healthy individuals in amounts up to at least 14 grams a day (2008), or about 3 teaspoons. Those experiencing L-glutamine depletion, either from normal aging or from stresses against good health, can tolerate higher doses.

L-Lysine HCl

L-Lysine HCl is the hydrochloride salt of L-lysine.

This is the most bioavailable form of the amino acid for manufacturing supplements. Its properties as a hydrochloride salt come from how easily the ionic form of L-lysine complexes with hydrochloride.

L-Lysine is one of the eight essential amino acids, meaning that you have to get it from food or supplements.

Several anti-aging benefits of L-lysine rest on its crucial role in the formation of collagen, which supports healthy hair, skin, and nails; muscles; and, joints (2011).

L-Lysine also helps to increase the absorption of circulating calcium. This role underscores the importance of L-lysine in maintaining healthy bones.

The well-known gradual loss of muscle mass and strength with age can be slowed significantly by including L-lysine supplementation in specific nutritional mixtures. This benefit is especially valuable in the elderly (2004).

A more recent discovery involving L-lysine points to its potential as a preventative against the development of Alzheimer’s disease (2010).

The idea behind this suggestion stems from the activity of L-lysine in preventing outbreaks of cold sores caused by the type 1 herpes simplex virus.

This virus is believed to contribute to the formation of neuro-fibrillary tangles and amyloid plaques that characterize Alzheimer’s disease.

Supplementation with L-lysine, as with other amino acids, is associated with few side effects. The U.S. Food and Drug Administration lists L-lysine HCl as a GRAS (Generally Recognized as Safe) substance at standard doses of up to 3 grams a day for adults (2011).

L-Lysine is, like L-glutamine, widely available from many sources. Again, make sure that the supplement you take carries the USDA Organic certification label.

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