## 1 Introduction
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**Component CAS No./EC No.** & **Characteristics** \\ \hline Phenylalanine 63-91-2/200-568-1 & Essential amino acid that is a key substrate in the production of norepinephrine, a chemical that transmits signals between nerve cells and the brain; keeps you awake and alert; reduces hunger pains; functions as an antidepressant, and helps improve memory [59]. \\ \hline Phosphorus 7723-14-0/231-768-7 & Forms the sugar-phosphate backbone of DNA and RNA. It is important for energy transfer in cells as part of ATP (adenosine triphosphate), and is found in many other biologically important molecules [60]. \\ \hline Potassium 7440-09-7/231-119-8 & An electrolyte that maintains an electrolyte gradient on cell surfaces, keeping at specific concentrations inside and outside of the cell; this impacts fluid and electrolyte balance, nerve transmission, muscle contraction, as well as cardiac and kidney function [61]. \\ \hline Progesterone 57-83-0/200-350-6 & Female sex hormone, a progestogen. Switches the proliferative phase into secretory phase of the endometrium (inner mucous lining of the uterus). Stimulation of progesterone receptors present in keratinocytes and skin fibroblasts helps in maintaining skin firmness and elasticity and inhibits sebum production [62]. \\ \hline Riboflavin 83-88-5/201-507-1 & Vitamin B2, essential to the formation of coenzymes involved in energy metabolism, cellular respiration, and antibody production, as well as normal growth and development, required for the metabolism of niacin, vitamin B6 and folate [63]. \\ \hline Selenium 7782-49-2/231-957-4 & Essential micronutrient, a component of the antioxidant enzymes glutathione peroxidase and thioredoxin reductase [64]. \\ \hline Serine 56-45-1/200-274-3 & Critical for the production of the body’s proteins, enzymes, and muscle tissue. Serine is needed for the proper metabolism of fats and fatty acids. It also helps in the production of antibodies. A natural moisturizing agent in some cosmetics and skin care products [65]. \\ \hline Sodium 7440-23-5/231-132-9 & An electrolyte important for many different functions of the human body. For example, it helps cells to transmit nerve signals and regulate water levels in tissues and blood [66]. \\ \hline Somatotropin 66004-58-8/- & Synonym: human growth hormone (hGH). Stimulates mitosis, cell differentiation, and cell growth. In the skin, directly and indirectly stimulates growth and differentiation of fibroblasts and keratinocytes. In the hair, the outer root sheath keratinocytes express hGH receptors, yet somewhat paradoxically recombinant hGH inhibits female hair follicles ex vivo [67]. \\ \hline Testosterone 58-22-0/200-370-5 & Male sex hormone, an androgen. Causes the development of masculine sex organs and secondary sexual characteristics. Increases sebum production in the skin and scalp, development of public, axillary and facial hair. Stimulation of testosterone receptors in skin fibroblasts helps in maintaining skin firmness and elasticity, in keratinocytes increases keratin production (keratosis). Together with its metabolite dihydrotestosterone a key factor in male baldness [68]. \\ \hline Thiamine 67-03-8/200-641-8 & Vitamin B1, essential micronutrient required for metabolic reactions including the breakdown of glucose and amino acids [69]. \\ \hline Threonine 80-68-2/200-774-1 & Essential amino acid that helps to maintain the proper protein balance in the body. It is important for the formation of collagen, elastin, and tooth enamel and supports hepatic and lipoprotein function when combined with aspartic acid and methionine [70]. \\ \hline Tryptophan 54-12-6/200-795-6 & Essential amino acid that is critical for the production of the body’s proteins, enzymes, and muscle tissue, essential for the production of niacin, serotonin and melatonin [71]. \\ \hline Tyrosine 60-18-4/200-460-4 & Conditionally essential amino acid that is critical for the production of the body’s proteins, enzymes, and muscle tissue, a precursor of the neurotransmitters norepinephrine and dopamine. It can act as a mood regulator and an anti-depressant. Tyrosine is the substrate in the production of melanin and plays a critical role in the production of thyroxin (thyroid hormones) [72]. \\ \hline Valine 72-18-4/200-773-6 & Essential branched-chain amino acid that enhances energy, increases endurance, and aids muscle tissue recovery and repair. Essential amino acid found in proteins; important for optimal growth in infants and children and for nitrogen balance in adults [73]. \\ \hline \hline \end{tabular}
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