Pentapeptide-30 Cysteinamide: What Is It, Cosmetic Uses, Benefits & Side Effects

Curious about this ingredient? In this article we're explaining exactly what it is and why it's used within cosmetic formulations.
Updated on: July 1, 2025
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We verify all information on this page using publicly available nomenclature standards from The Personal Care Products Council (PCPC), the European Commission's CosIng database and documentation provided directly by ingredient manufacturers. Our analysis is based on technical data from these sources to ensure accuracy and reliability.

What Is Pentapeptide-30 Cysteinamide?

Pentapeptide-30 Cysteinamide is a small chain of five amino acids (a pentapeptide) that has been linked with the naturally occurring amino acid cysteine through a reaction called amidation. The result is a stable, water-soluble molecule that can easily mix into modern cosmetic formulas. Peptide research took off in the early 2000s as brands searched for gentle bioactive ingredients, and chemists soon noticed that pairing short peptides with cysteine increased their ability to bind to hair and skin. Today manufacturers create Pentapeptide-30 Cysteinamide in the lab by first synthesizing the pentapeptide through solid-phase peptide chemistry, then reacting it with cysteine under controlled conditions to form the cysteinamide bond. Because it is produced in a sterile environment, the final ingredient is uniform in quality and free of animal-derived material, making it suitable for vegan formulas. You will most often see Pentapeptide-30 Cysteinamide in rinse-off and leave-in hair masks, conditioners, anti-breakage serums, scalp treatments and multitasking styling creams that promise smoother, healthier-looking strands.

Pentapeptide-30 Cysteinamide’s Cosmetic Benefits/Uses

This peptide’s main value in beauty products comes from its hair conditioning ability.

As a hair conditioning agent, Pentapeptide-30 Cysteinamide helps coat the hair shaft, improving slip and manageability while reducing friction that can lead to breakage. Its peptide backbone is small enough to reach damaged areas, where it can form a lightweight film that smooths cuticles and boosts shine. Regular use can leave hair feeling softer and looking more resilient, which explains why formulators often add it to products aimed at dry, brittle or chemically treated hair.

Who Can Use Pentapeptide-30 Cysteinamide

Because it is a lightweight, water-soluble peptide, Pentapeptide-30 Cysteinamide suits all scalp and hair types, including oily, dry, color-treated and textured hair. It is non-comedogenic and non-occlusive so it will not clog follicles or weigh strands down. There are no known skin or scalp types that should routinely avoid it, though anyone with a confirmed allergy to peptides or cysteine derivatives should proceed with caution.

The ingredient is produced by chemical synthesis without animal-derived materials, making it appropriate for both vegetarians and vegans. Manufacturers often highlight this in “cruelty-free” or “vegan formula” claims.

No data suggest that Pentapeptide-30 Cysteinamide poses a specific risk to women who are pregnant or breastfeeding when used topically in rinse-off or leave-in hair products. This is not medical advice and pregnant or nursing individuals should review any new personal care product with their healthcare provider to be safe.

Pentapeptide-30 Cysteinamide does not increase photosensitivity, so it will not make hair or scalp more prone to sun damage. It is also compatible with common styling ingredients such as silicones, plant oils and mild surfactants.

Potential Side Effects/Adverse Reactions

Side effects or reactions to topical Pentapeptide-30 Cysteinamide vary from person to person. The following list covers potential issues yet these events are uncommon when the ingredient is used correctly in well-formulated products.

  • Mild scalp or skin irritation such as redness itching or dryness
  • Allergic contact dermatitis in individuals sensitive to peptide fragments or cysteine derivatives
  • Temporary stinging or tingling if applied to broken or freshly exfoliated skin
  • Protein buildup that can leave hair feeling stiff or coated when combined with multiple protein-rich products

If any unwanted reaction occurs discontinue use immediately and consult a healthcare professional or dermatologist.

Comedogenic Rating

Rating: 0 / 5

Pentapeptide-30 Cysteinamide is a small, water-soluble molecule that rinses clean without leaving a greasy residue. It lacks heavy oils or waxes that could block pores so it earns a solid 0. This makes it suitable for people who are prone to acne or breakouts.

No data suggest that it contributes to follicular buildup or scalp acne. Its lightweight film-forming action targets hair shafts rather than skin, further reducing any pore-clogging risk.

Summary

Pentapeptide-30 Cysteinamide is a lab-crafted peptide linked to cysteine that conditions hair by forming a thin smoothing layer, reducing friction and enhancing shine. It mixes easily into both rinse-off and leave-in products, offers vegan credentials and is gentle enough for daily use.

While not as famous as argan oil or keratin, it is gaining traction among indie and salon brands that focus on science-backed peptides for hair repair.

Overall safety is high with low irritation potential and a non-comedogenic profile. As with any new cosmetic it is wise to perform a quick patch test to rule out individual sensitivities before full use.

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