My skin seems to love serums with amino acids. This should probably be obvious, since amino acids make up 75% of the human body. They are essential to almost all bodily functions and chemical reactions. The complexity of amino acids, their role in building proteins and how they can enhance our skincare regimens are becoming better understood all the time. Result: some excellent anti-aging skincare products.

There are around 20 different kinds of amino acids. Eight of them are considered "essential" for humans because they cannot be created from other compounds by the human body, so they must be taken in as food. These amino acids are isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan and valine. All of them are needed to make a human protein molecule.

Speaking of proteins, amino acids are the building blocks of proteins. They band together in chains to form the stuff from which life is born. This is a two-step process: first, they get together and form peptides or polypeptides, and it is from these groupings that proteins are made. Two amino acids joined in a peptide bond constitute a dipeptide, three a tripeptide, several an oligopeptide, and many a polypeptide. A protein can be made up of just one or multiple polypeptides.

Now, let’s get down to the important business of aging skin. Among other things, amino acids are an essential part of the synthesis of collagen and elastin. When the supply of amino acids is reduced, it affects the renewal of cells, which causes, in particular, the thinning of dermis. So, one would hope that putting amino acids back will help collagen and elastin production. It does, but not just any old amino acids.

For example, a study in an academic publication called (appropriately) "Amino Acids,” demonstrated that “branched-chain amino acids” along with two specific amino acids, glutamine or proline, restored collagen synthesis after UV exposure.

Proline is a particularly good amino acid to go for. Hydroxyproline (synthesised from proline) is a major component of the connective tissue collagen. Proline has the ability to strengthen and renew aging skin cells. One-sixth of collagen, a major building block of skin (and its youthful appearance), is comprised of proline.

Another is carnitine, which makes itself useful in lipid transport. It is also supposed to curtail age-related oxidation and may have an ability to break down fat cells — hence, it turns up in cellulite creams. Meanwhile, leucine repairs aging skin tissue and aids in wound healing.

Serums, moisturizers and even hair care products with amino acids should have most of the essential ones. Here are some that have amino acids and much, much more:

ReLuma Anti-aging Moisturizer ($85) has 10 amino acids and ReLuma’s signature human conditioned media (stem cells).

Skin Nutrition Cell CPR ($170) has proline and tyrosine, apple stem cells and peptides. Cell CPR’s formula mimics the proteins, phospholipids, vitamins and minerals found in the skin.

Truth Vitality Advanced Complex ($59 in the shop) is our copper peptides-based hair growth serum. The copper peptide complex is based on amino acids and copper chloride and aids healthy hair growth while reducing shedding. The same complex, along with emu oil, is in the new Truth Vitality True Volume Shampoo ($29 in the shop).

Sweetsation Q*Lumiere Organic Day Creme ($29) with 11 amino acids, CoQ10, brightening ingredients and an orchard of fruit extracts.

BRAD Biophotonic Essential Elixir Multi-Peptide ($95) is all about amino acids with a blend of 13 silk amino acids. There’s witch hazel and hyaluronic acid, and my skin just looks happy from using it.  I also love BRAD Biophotonic Sublime Youth Creator Gel-Cream ($245), which also has the silk amino acid blend as well as Matrixyl 3000.

Sciote Vitamin C Eye Treatment ($60) Sciote’s “peptide complex blend” has 13 amino acids and a 5% concentration of vitamin C.

Mukti Age Defence Night Serum ($91) has proline, alanine and serine, as well as niacinamide and some great botanical extracts.

M.A.D Skincare Eye Defense Shielding Serum ($60) contains peptides, fruit extracts and amino acids.

Astara Age Defying Complex ($85) hydrates with phospholipids and hyaluronic acid, plus there’s royal jelly and, of course, the amino acids.

E'shee Clinical Esthetic Elixir of Life KI Therapy Serum ($189 in the shop) is one of my all time favorites, with arginine, alanine and glutamic acid, growth factors and far infrared ceramic powder.