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INCI: Phenylalanine

What is Phenylalanine?

Phenylalanine is an essential amino acid since our body needs the same to synthesize protein and repair tissues.  It has to be obtained from the food and our body can not make it on its own. Phenylalanine is also a precursor of tyrosine and skin pigment melanin. It is naturally found in milk, meat, eggs, soybean, etc. Amino acids have a unique chemical structure, since they have both a basic/ amino (-NH2) and an acidic / carboxyl (-COOH) in one molecule.  Because of this structure, it can form temporary bonds with other groups which stabilize the product as well. 

Use & Benefits:

Phenylalanine is primarily used as a skin and hair conditioning agent. It has also a medicinally major use in skin discoloration. As mentioned earlier because of its unique structure, it forms a barrier on the surface of the skin. When applied to the skin and hair, it reduces water loss. It keeps skin and hair hydrated. It also reduces aging effects like wrinkles, fine lines, and dark spots formed on the skin due to aging and exposure to external factors. Its modified molecule undecylenoyl phenylalanine may inhibit the production of melanin and reduces hyperpigmentation. It is also a part of peptides that are called signal peptides and reduces the formation of collagenase.  It lightens the skin and makes it more radiant and refreshed. It is used in creams, lotions, sun care products, and other skin and hair care products.

How to create your own Personalized Skincare with Lesielle?

Icons of the lesielle custom skin care system

Step 1: Select a nourishing base compatible with your skin, and your desired moisturization level

Step 2: Complete your treatment with up to four active ingredients for consistent and occasional use.

Step 3: Insert your base and up to four actives ingredients into your Lesielle device to produce a fresh single dose of face cream on demand when you need it.

Complete your routine with a cleanser and other complimentary products and accessories.


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The skincare system for an ever evolving skin, using recognized active ingredients with scientifically proven efficacy to create treatment tailored to each day's State of Skin. 

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