CuratedFit
CURATEDFIT SUMMARY
Passes because this is a single active ingredient, L-Lysine as the HCl salt form, with an exact, disclosed dose. Lysine is produced almost exclusively via bacterial fermentation industrially, it's the most heavily fermented amino acid in the world by production volume, so this sits on the favorable side of the natural-origin question the way leucine and beta-alanine do, unlike methionine.
WHAT IT IS
A vegetarian capsule providing 620mg of L-Lysine (as L-Lysine HCl), an essential amino acid the body can't produce on its own and must obtain through diet or supplementation. Lysine is one of the amino acid building blocks used in collagen synthesis, alongside glycine and proline.
WHO IT IS FOR
Someone specifically supporting the body's own collagen production, most relevantly here, as one of three individually sourced amino acid building blocks (alongside glycine and proline) paired with vitamin C in the Vegan Muscle Building basket's collagen-support tier, rather than relying on a "vegan collagen" product, which doesn't meaningfully exist as an equivalent to actual collagen.
INGREDIENT BREAKDOWN
L-Lysine (as L-Lysine HCl)
620mg
Free-form amino acid, hydrochloride salt. A single, disclosed active. The suggested use is 1 capsule up to three times daily, on an empty stomach, working out to as much as 1,860mg daily at the full suggested intake. Worth noting a second amino acid, L-Leucine, appears in the other ingredients list, likely functioning as a processing aid rather than a dosed active, no separate amount is disclosed for it, so it isn't evaluated as a second active ingredient here.
Other ingredients
Vegetable Cellulose (capsule), Vegetable Stearate, L-Leucine
CERIFICATIONS
Informed Sport
Not Confirmed
Banned substance tested
Not Confirmed
GMP Certified
Not Confirmed
Heavy metals tested
Not Confirmed
BRCGS
Not Confirmed
FSSC 22000
Not Confirmed
CURATEDFIT STANDARD CHECK
Pass
As Natural As Possible
Lysine is produced almost exclusively via bacterial fermentation industrially, the dominant commercial route for this specific amino acid, favorable by the same industry-pattern reasoning already applied to leucine.
Info
Contains What It Claims
No independent lab verification of the 620mg amount was found. Manufacturer stated.
Pass
Every Ingredient Earns Its Place
Standard capsule excipients plus a small, undosed amount of L-Leucine, likely a processing aid; nothing undisclosed.
Pass
No Insect-Derived Ingredients
No animal or insect-derived ingredients.
Pass
No Proprietary Blends
Single active ingredient with an exact disclosed dose.
Info
Allergen Declaration
No explicit allergen statement found beyond the ingredient list.
Pass
Sugar Content Declared
No sugar present.
Pass
Artificial Sweeteners and Flavorings
None present.
Info
Heavy Metals and Contaminants
Not disclosed on the page reviewed.
Pass
Banned Substance Risk Declared
A standard essential amino acid, not a banned substance.
Info
Country of Manufacture Noted
Not confirmed on the page reviewed.
TRANSPARENCY NOTE
Lysine's role in collagen synthesis is as a structural building block, alongside glycine and proline, rather than a synthesis trigger the way vitamin C functions as an enzymatic cofactor. The manufacturer's own marketing leans heavily on other benefits, calcium metabolism, stress response, nitrogen balance, none of which are the reason this product is included in this basket. Worth being precise: this is sourced specifically for its collagen-building-block role, and the suggested three-times-daily dosing (up to 1,860mg total) is the manufacturer's general suggested use, not a dose calibrated specifically against collagen synthesis research.
FREQUENTLY ASKED QUESTIONS
Why lysine specifically, alongside glycine and proline?
Collagen is unusually rich in these three amino acids relative to other proteins. Supplying them individually supports the body's own collagen-building process, rather than attempting to supply collagen itself from a plant source, which doesn't exist.
Is this the same as taking a "vegan collagen" product?
No, and that's deliberate. Most vegan collagen products are large, undisclosed proprietary blends that fail this Standard's transparency criteria. This approach sources the individual, disclosed building blocks instead.
Does lysine do anything beyond supporting collagen?
The manufacturer notes several other studied roles, calcium metabolism, stress response, nitrogen balance. Those aren't the reason this product was sourced for this basket, but they're accurately part of what the ingredient is studied for.
Last reviewed:
8/16/26
Life Extension L-Lysine, Life Extension Europe UK product page, including manufacturer stated supplement facts panel.
Sources:
Last updated:
8/16/26
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