We don’t treat science as decoration. It’s the foundation of everything.
YLW was created by two research analysts who spent years separating strong data from weak claims. That mindset shapes everything we make. Every ingredient, dose and delivery method is chosen because it’s backed by real evidence and works in real bodies — not because it sounds impressive on a label.
Our approach is pragmatic: bring together leading experts in microbiology, nutrition and cosmetic science; use peer-reviewed research to guide the formulas; and test every batch for purity.
100+
Peer-reviewed papers
Supporting the specific probiotic strains and bioactives used in our formulations.
103,000+
Scientific citations
Across Professor Glenn Gibson’s work in gut health and the microbiome
21bn+
Live CFU per capsule
Across our multi-strain Day Pill, delivered in a delayed-release capsule to reach the colon alive.
Zero
Filler ingredients
No fad actives, no unnecessary additives — only ingredients with a clear role and evidence behind them.
Our Supplements
Our supplements are built on two principles: biological synergy and clinical proof. Each formula targets the body’s core systems — gut, sleep and skin — because they work better together than alone.
Clinical proof
Every key strain and nutrient is backed by peer-reviewed research. We use evidence, not trends, to shape each formulation.
Optimal dosing
Each capsule delivers meaningful, evidence-based levels in highly bioavailable forms — nothing underdosed, nothing unnecessary.
Targeted delivery
We match the delivery system to the science — including delayed-release capsules for probiotics and carefully dosed night-time formulas.
Real-world testing
Every formula is tested with real people, and each batch is independently lab-tested for purity — so results are measurable, visible and genuinely felt.
Meet nutritional researcher, Sophie Medlin
Our Head of Nutritional Research, Sophie Medlin, leads the development of YLW’s supplement formulations.
In this short film, she explains how every product begins — from analysing real diets to identifying what the body truly needs and selecting ingredients with proven impact.

Meet food microbiologist, Glenn Gibson
Professor of Food Microbiology at the University of Reading, Glenn Gibson co-coined the term prebiotics and has published over 500 scientific papers. He advises YLW on how gut health influences the body’s wider systems — including the skin.
In this short film, he explains how YLW’s multi-strain probiotics are designed to work in harmony, using a delayed-release capsule to ensure each strain reaches the gut intact and active.
Our Skincare
We treat skin as the body’s mirror — a reflection of what’s happening within. Our skincare is designed to work with your biology, complementing the internal regime and supporting the skin barrier, hydration and clarity with evidence-led actives.
The result is skincare that feels luxurious, behaves intelligently, and earns its place through visible results, not promises.
Barrier Support
Formulated using cosmetic science and microbiome research to strengthen the skin’s natural defences and reduce reactivity over time.
Cell Renewal
Uses next-generation bio-retinoid technology and supportive actives to refine texture and encourage consistent, healthy radiance.
Deep Hydration
Combines clinically proven humectants with lipid-supporting ingredients to lock in long-lasting hydration and restore suppleness.
Visible Balance
Designed to promote even tone, calmness and clarity — visible signs of a well-regulated skin ecosystem.
Our scientific team
Behind every formula is a partnership between leading experts in microbiology, nutrition and cosmetic science. Together, they bridge academic research and real-world results — turning peer-reviewed evidence into formulations that genuinely perform.
Sophie Medlin
Chair of the British Dietetic Association (London) and former lecturer at King’s College London. Oversees supplement development, ensuring ingredient choice and dosing are grounded in peer-reviewed evidence and real-world efficacy.
Professor Glenn Gibson
Co-coined the term prebiotics in 1995. Author of 8 books, over 500 research papers, and more than 400 abstracts with 56,000+ career citations. Advises YLW on probiotic strain selection and gut-skin axis research.
Daniel Whitby
Over 25 years’ experience developing advanced cosmetic formulations and patented technologies. Leads YLW’s formulation science, ensuring skincare delivers proven results with precision and safety.

