Tetrapeptide-21
A peptide identified by the brand as part of TEGO PEP 4-17.
The ingredient is one part of a product. The formula is the whole mixture. A number such as 29 or 1 identifies a name; it is not a strength or quality score.
Exact label name: Tetrapeptide-21Type of support: Label information
What it is
A distinct peptide listed on the Power Peptides label. The number 21 is an identifier, not a strength score.
Why it is used
Geek & Gorgeous describes it within a blend marketed for the appearance of skin firmness.
What the evidence means
The recorded support is manufacturer information about labels and ingredient systems. It does not establish how well this ingredient alone works in these finished serums.
Precautions and possible reactions
An ingredient-specific side-effect rate is not established by these sources. Check the complete product label and follow its current instructions.
Cosmetics can cause irritation or allergic reactions. Check the full ingredient list and follow product directions.
What this means for your comparison
Recognize the exact ingredient name, then consider the whole product. Neither its number nor a blend percentage tells us which serum will work better for you.
Sources checked . Ingredient information is separate from testing a finished serum.

