Streptococcus Lactis Extract: 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: June 30, 2025
Share:
Inside this article:

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 Streptococcus Lactis Extract?

Streptococcus Lactis Extract is a skin care ingredient obtained from the cultured bacteria Streptococcus lactis, a species more familiar for its role in fermenting dairy products. When grown in controlled laboratory conditions the bacteria produce a broth rich in proteins, peptides and sugars. After the culture finishes fermenting, technicians filter out the cells and water down the remaining liquid, then gently dry or concentrate it to create a stable extract suitable for creams and serums.

The cosmetic world began exploring bacterial ferments in the late twentieth century when scientists noticed that some by-products of fermentation helped keep skin calm and balanced. Streptococcus Lactis Extract entered formulas as part of this wave, prized for its soothing and protective properties. Today you are most likely to see it in moisturizers, barrier-repair lotions, calming masks, hydrating essences and post-exfoliation treatments where keeping the skin’s surface strong is the main goal.

Streptococcus Lactis Extract’s Cosmetic Benefits/Uses

In skin care, Streptococcus Lactis Extract is valued primarily for one key role

Skin protecting: By forming a light film of moisture-binding proteins and sugars on the surface, the extract helps reinforce the skin barrier. A stronger barrier means less transepidermal water loss so skin stays supple and hydrated, it also means fewer chances for external irritants like pollution particles to penetrate. When included in a formula, this ingredient can make the overall product more soothing, reduce redness linked to dryness and support long-term resilience in all skin types.

Who Can Use Streptococcus Lactis Extract

Most skin types tolerate Streptococcus Lactis Extract well, including dry, normal, combination and sensitive skin because its main job is strengthening the barrier rather than exfoliating or stripping. Oily or acne-prone users can also benefit as the extract itself is lightweight and non greasy, though they should check the full formula to be sure it is not overly rich.

The ingredient is produced from bacteria, not animal tissue, so it can be suitable for vegans and vegetarians when grown on plant-based or synthetic culture media. Brands that cater to a vegan audience usually confirm the fermentation substrate on their product page or packaging.

Current research has not flagged the extract as a risk during pregnancy or breastfeeding. It does not penetrate deeply and is used at low levels, however this is not medical advice and anyone who is pregnant or nursing should ask a doctor before adding new products to their routine.

Streptococcus Lactis Extract does not increase photosensitivity so there is no special need to avoid sunlight after application beyond normal daily sunscreen habits.

Potential Side Effects/Adverse Reactions

Individual responses to topical Streptococcus Lactis Extract can vary. The effects listed below are only potential issues and are unlikely when the ingredient is properly formulated and used as directed.

  • Allergic contact dermatitis – very rare but possible in people with specific sensitivities to bacterial proteins
  • Transient stinging or redness – may occur if applied to severely compromised or freshly exfoliated skin
  • Breakouts linked to supporting ingredients – formulas that pair the extract with heavy oils or waxes might clog pores in acne-prone skin even though the extract itself is non comedogenic

If any unwanted reaction occurs discontinue use and seek advice from a healthcare professional

Comedogenic Rating

Rating: 0/5

Streptococcus Lactis Extract is water based and contains mainly low-molecular-weight proteins and sugars that do not clog pores. It has no oils, waxes or fatty acids typically linked to comedogenicity, which is why it sits at the lowest end of the scale.

This makes the ingredient suitable for people prone to acne or breakouts, provided the rest of the product is also lightweight and non greasy.

Keep in mind the final formula matters most; if the extract is blended with rich emollients the product could still be pore-clogging even though the extract itself is not.

Summary

Streptococcus Lactis Extract is mainly used as a skin-protecting agent. The fermentation process leaves behind proteins, peptides and sugars that form a sheer film on the surface, helping lock in moisture and strengthen the barrier so skin stays calm and resilient.

While not a superstar in every beauty aisle, the extract has a steady following in barrier-supportive moisturizers, calming essences and post-treatment products, especially within niche and K-beauty inspired lines.

Current data points to a high safety profile with very low irritation risk, though every skin is unique. It is always wise to patch test any new product containing Streptococcus Lactis Extract to confirm personal tolerance before full-face use.

Was this article helpful?
More from Glooshi:
ADVERTISEMENT
Get all our top headlines in beauty.
Delivered right to your inbox each week. Zero spam, all goodness, opt-out at anytime.
This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.
Get the latest beauty news, top product recommendations & brand-exclusive discount codes direct to your inbox.
Send good feedback:

All feedback is greatly appreciated, anonymous, and will be used to improve the quality of our articles.

This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.
Send bad feedback:

All feedback is greatly appreciated, anonymous, and will be used to improve the quality of our articles.

This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.
Search