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Pai Labs Peptides 5% Smoothing Booster
Pai Labs Peptides 5% Smoothing Booster

Peptides 5% Smoothing Booster

£19.00

10ml / 0.3 fl.oz

A concentrated dual-peptide booster that plumps sensitive skin and softens fine lines. Science & naturals combine for serious effectiveness while minimising irritation. That's what we do!

Plumping

Firming

Hydrating

Collagen boosting

Boosts Elasticity

Free delivery when you spend £30* | 90-Day returns

Free Mini Light Work™ Cleansing Oil when you spend £65+

Peptides 5% Smoothing Booster

£19.00

•

Vegan

•

Powered By Green Chemistry

•

Cruelty Free
Why You'll Love It

A dual-peptide booster to firm and smooth.

Most peptide products rely on synthetic actives. Ours are naturally derived, yeast-fermented and plant-fermented, and COSMOS certified. That's genuinely rare in the peptide world, and it means you get real anti-ageing performance within a fully natural formula.

We've paired Hexapeptide-11 with Pea Peptide, and they work as a team. The hexapeptide sends the signal, telling your skin's fibroblasts to ramp up collagen and elastin production. The pea peptide supplies the building blocks, particularly lysine, an essential amino acid your body can't make on its own and one that's critical for strong, stable collagen fibres. The result: firmer, bouncier skin with a noticeably smoother finish.

A little-known fact about peas: they have one of the most balanced amino acid profiles of any vegetable protein, containing all 22 amino acids. That richness also means film-forming and antioxidant benefits on the skin's surface, so you get both deeper support and an immediate smoothing feel.

Hexapeptide-11 is backed by published research showing measurable improvement in skin elasticity in just 4 weeks. It also activates your skin's own antioxidant defence system (the Nrf2 pathway) and helps protect fibroblasts from the premature shutdown that accelerates visible ageing.

Directions

Add 1–2 drops to your moisturiser, blend together in your palm, and apply as normal. That's it. Two drops doing some seriously heavy lifting.

Use morning and evening for the full collagen-stimulating effect, or evenings only if that suits your routine better. For targeted smoothing around the eye area (yes, it's gentle enough), add a single drop to your eye cream instead.

Want to really go for it? Pai's lead chemist rates Peptides + Hyaluronic Acid 0.3% as the dream team for ageing skin: firming, smoothing and deep hydration in one step. It also pairs brilliantly with Stabilised Vitamin C 20% if brightening is on your list too.

Full Ingredients

Aqua (water), Pentylene Glycol, Pisum Sativum Peptide (pea), Methylheptylglycerin, Glycerin, Xanthan Gum, Cellulose, Hexapeptide-11, Leuconostoc/radish Root Ferment Filtrate, Sodium Hydroxide, Sodium Phytate, Glyceryl Caprylate, Tocopherol* (vitamin e).

99.99% natural origin.

*Organic

Recycling

Say no to landfill! Let's recycle everything! - Sarah

Unscrew the dropper and remove it from the glass bottle. Gently pull the glass pipette out of the dropper. Rinse the glass bottle and pipette, then place both into your household recycling. Pop the dropper and rubber bulb into your Pai mailer to send back to us for specialist recycling.

All Pai boxes, cartons, sleeves and inserts can be recycled with your household paper recycling.

The majority of your Pai packaging can be recycled at home, but some components need specialist recycling. We've partnered with a specialist programme to make this as easy as possible for our UK customers.

Keep your Pai mailer box (it can be flat packed for easy storage). Fill it with the packaging elements you can't recycle at home, and clearly label the box RECYCLING. Create your free returns label and drop it off at the post office.

Please note we are unable to accept glass or non-Pai packaging. Glass bottles can be separated and placed into your household recycling.

If you are in the UK and unsure what your local services accept, visit recyclenow.com.

Key Ingredients

  • Peptides

    If plump, bouncy, youthful skin is your goal, this one’s for you. Peptides are clever amino acids best known for stimulating collagen and elastin - meaning fewer lines and firmer skin. Ours is all-natural: yeast-derived Hexapeptide joins the humble yet hardworking Pea Peptide, rich in lysine to support healthy skin.

Sarah Brown, Pai Founder

"Think of applying Peptides as putting up skin scaffolding; the building blocks of proteins, these amino acids tell your skin that it’s time to do some rejuvenation work. They can prompt the generation of collagen and elastin - the two proteins that form the skin’s infrastructure - resulting in plumping, firming and fewer fine lines."

SARAH BROWN
FOUNDER, PAI SKINCARE

Frequently Asked Questions

Who is Peptides 5% best suited for, and when should I start using it?

Peptides 5% is ideal if you're noticing early or established signs of ageing: fine lines, loss of firmness, reduced elasticity, or skin that's starting to feel thinner. Since collagen production drops by roughly 1% per year from your twenties, introducing peptides in your late twenties to mid-thirties is a smart preventative move, though it's equally effective on more mature skin. Its gentle, fragrance-free formula makes it a particularly good choice if your skin is too reactive for stronger anti-ageing actives like retinoids.

What results can I expect from Peptides 5%, and how quickly?

The lead active, Hexapeptide-11, showed measurable improvement in skin elasticity after just 4 weeks in an in vivo study on 25 volunteers. You can expect firmer, smoother-feeling skin with reduced appearance of fine lines over consistent use, while the pea peptide's film-forming action gives an immediate smoothing and moisture-retaining effect from first application.

How do I use the Peptides 5% Booster?

Add 1-2 drops to your moisturiser and apply as normal, morning and evening or evenings only. For targeted eye area treatment, add 1 drop to your eye cream instead. Pai's lead chemist recommends pairing it with Hyaluronic Acid 0.3% Booster for the best combination for ageing skin, covering firming, smoothing, and hydration in one routine.

Is Peptides 5% suitable for sensitive skin?

Yes. It's fragrance-free, essential oil-free, and non-comedogenic, so it won't clog pores or trigger irritation. Every batch undergoes 96-hour patch testing on volunteers with sensitive skin, which goes beyond standard industry requirements. It's gentle enough to use around the delicate eye area and on highly reactive skin types.

Is this suitable for all skin types, including oily or combination skin?

Yes. It's a lightweight, water-based formula, so it won't add heaviness or greasiness. Because you're mixing just 1-2 drops into your existing moisturiser, the texture of your routine stays exactly the same, making it easy to layer even on oily or combination skin.

Can I use Peptides 5% during pregnancy or breastfeeding?

Yes, Peptides 5% is confirmed safe for use during pregnancy and breastfeeding. It contains no retinoids, synthetic actives, or essential oils, making it a straightforward option for firming and smoothing support when your ingredient choices are more limited.

What does the 5% concentration actually mean?

The 5% is the combined total of both peptides: 0.375% Hexapeptide-11 and 4.9% pea peptide. These two actives work at very different concentrations because they have different jobs. Signal peptides like Hexapeptide-11 operate through receptor-mediated cell signalling, so they're effective at low doses. For context, Pai's Retinal Booster is just 0.16% while the Vitamin C Booster is 20%. Both concentrations here sit within the supplier-recommended ranges for optimal performance.

What does Hexapeptide-11 do for my skin?

Hexapeptide-11 is a yeast-fermented signal peptide that instructs your fibroblasts to ramp up collagen and elastin production. It also activates the Nrf2 pathway, your cells' master antioxidant defence system, and protects fibroblasts from premature senescence, the process where they stop building structural proteins and start secreting pro-inflammatory molecules that accelerate visible ageing.

What role does the pea peptide play in this formula?

Pea peptide is a 15-amino-acid chain produced through Lactobacillus fermentation at a controlled molecular weight of around 2,000 Da, making it substantially larger than the signal peptide because its job is different: supplying raw materials. It delivers all 22 amino acids, and is especially rich in lysine, the essential amino acid your body can't make on its own but needs for the hydroxylysine cross-links that give collagen fibres their structural strength (Yamauchi & Sricholpech, Biochemistry Journal, 2012).

Why does the formula include prebiotic inulin?

Inulin, derived from chicory root, selectively feeds beneficial skin bacteria like Lactobacillus and Bifidobacterium while inhibiting pathogens such as Staphylococcus aureus. This supports a healthy skin microbiome that reinforces your skin barrier alongside the peptide actives. It's a standard inclusion across all Pai Labs Boosters.

What certifications does Peptides 5% hold?

It's COSMOS Natural certified, Vegan, and Cruelty-Free with Leaping Bunny certification. The formula is 99.99% natural and free from parabens, silicones, sulfates, alcohol, fragrance, essential oils, and gluten. Pai is also a certified B Corp.

How does Peptides 5% differ from Pai's Vegan Collagen and Retinoid boosters?

Each targets ageing through a different mechanism. Peptides 5% stimulates your skin's own collagen and elastin production through cell signalling. Vegan Collagen 0.9% provides topical conditioning with a plant-derived collagen analogue. Retinoid 0.3% accelerates cell turnover through retinoid activity. They can be used individually or combined depending on your priority concern.

What clinical evidence supports the peptides in this formula?

Hexapeptide-11 is backed by peer-reviewed research (Sklirou et al., Redox Biology, 2015; PMID: 25974626). An in vivo skin deformation assay on 25 volunteers confirmed measurable improvement in skin elasticity after 4 weeks, while in vitro studies on human dermal fibroblasts showed upregulation of genes responsible for collagen, elastin precursors, and hyaluronic acid production.

Pea peptide's antioxidant capacity, amino acid profile, and film-forming properties are supported by supplier data, including an ORAC study against a vitamin E analogue control. This is all ingredient-level evidence; the finished Peptides 5% formula has not undergone its own efficacy trial.

What makes Peptides 5% different from other peptide serums?

Most peptide serums use synthetic peptides in conventional formulations. Pai's Peptides 5% uses two naturally derived peptides, one yeast-fermented and one plant-fermented, making it one of very few peptide products that qualifies for COSMOS Natural certification. It also pairs a signal peptide (which tells your skin to produce more collagen and elastin) with a substrate peptide (which supplies the amino acid building blocks to do it), rather than relying on a single peptide type.

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