We've done the science,
so you don't have to.
Grey Muzzles is a daily treat built around natural antioxidants, chosen after reviewing the research on healthy ageing in dogs.
The pathways below are the four areas we focused on. For the curious, a selection of the published research we drew on is linked further down.
Everyday antioxidant support
As dogs age, their bodies work harder to keep everything in balance. Our recipe brings together natural antioxidants to help with that daily job.
Comfortable movement
Mobility is one of the biggest quality-of-life factors for older dogs. Our ingredients were chosen with joint comfort and everyday muscle in mind.
Skin & coat
Good nutrition shows up in the coat first. Omega-3s and quality proteins help support the shine and softness of a happy senior dog.
Long-term vitality
Healthy ageing is many small things working together — bright eyes, an easier morning, a tail that still wags at the door.
A selection of the research.
A curated list of published studies that informed our thinking. Filter by topic, or open a paper to read a plain-language summary.
- Canine Nutrition Evidence · 2019
Effects of astaxanthin supplementation in healthy and obese dogs
T. Murai et al.
Summary
A canine study evaluating astaxanthin supplementation in healthy and obese dogs, reporting changes in antioxidant function and lipid-related markers.
Why it matters for Grey Muzzles
One of the few studies performed directly in dogs. Supports our use of astaxanthin as part of a daily antioxidant approach.
AstaxanthinOxidative BalanceExercise Recovery - Mechanistic Evidence · 1998 · Inflammation Research
Antioxidant and anti-inflammatory properties of C-phycocyanin from blue-green algae
C. Romay, J. Armesto, D. Remirez, R. González, N. Ledón, I. García
Summary
Foundational study examining antioxidant and anti-inflammatory properties of C-phycocyanin in experimental models.
Why it matters for Grey Muzzles
Establishes the mechanistic basis for why C-phycocyanin is studied in the context of oxidative and inflammatory balance.
C-PhycocyaninOxidative Balance - Published Literature · 2003 · Current Protein & Peptide Science
C-phycocyanin: a biliprotein with antioxidant, anti-inflammatory and neuroprotective effects
C. Romay, R. González, N. Ledón, D. Remirez, V. Rimbau
Summary
Review article summarising research on C-phycocyanin as a biliprotein studied for antioxidant, anti-inflammatory and neuroprotective mechanisms.
Why it matters for Grey Muzzles
A canonical reference for the biological interest of C-phycocyanin, a naturally occurring compound in Galdieria.
C-PhycocyaninOxidative Balance - Ingredient Characterisation Literature · 2016 · International Journal of Biological Macromolecules
Characterization of the highly branched glycogen from the thermoacidophilic red microalga Galdieria sulphuraria
M. Martinez-Garcia et al.
Summary
Characterises the unusually highly branched glycogen produced by Galdieria sulphuraria, structurally distinct from typical starches.
Why it matters for Grey Muzzles
Documents one of the properties that makes Galdieria a distinctive functional ingredient platform.
GaldieriaIngredient Characterisation - Preclinical Research · 2017 · Carbohydrate Polymers
The glycogen of Galdieria sulphuraria as alternative to starch for slowly digestible and resistant glucose polymers
M. Martinez-Garcia et al.
Summary
Explores the structure-property relationship of Galdieria glycogen and its relevance as a source of functional carbohydrate polymers.
Why it matters for Grey Muzzles
Reinforces the case for Galdieria as more than a colourant or protein source: a source of functional carbohydrate biology.
GaldieriaIngredient Characterisation - Published Literature · 2017
Functional carbohydrates from the red microalga Galdieria sulphuraria
M. M. Garcia (University of Groningen)
Summary
Positions Galdieria sulphuraria as a source of two carbohydrates of industrial interest: highly branched glycogen and floridoside.
Why it matters for Grey Muzzles
Frames the broader ingredient platform we build around, well beyond simple algae biomass.
GaldieriaFloridosideIngredient Characterisation - Preclinical Research · 2016
Floridoside production by the red microalga Galdieria sulphuraria under different conditions of growth and osmotic stress
Multiple authors
Summary
Investigates floridoside accumulation in Galdieria under different growth and osmotic stress conditions.
Why it matters for Grey Muzzles
Illustrates how Galdieria naturally produces protective molecules in response to environmental stress.
GaldieriaFloridosideCellular Resilience - Published Literature · 2024
Significance and Applications of the Thermo-Acidophilic Microalga Galdieria sulphuraria
B. Retta et al.
Summary
Review discussing the biology and applications of Galdieria sulphuraria as a thermo-acidophilic microalga.
Why it matters for Grey Muzzles
A recent overview of why Galdieria is being studied across nutrition, biotechnology and healthy ageing research.
Galdieria - Preclinical Research · 2022
Cell adaptation of the extremophilic red microalga Galdieria sulphuraria 074W
P. Perez Saura et al.
Summary
Study of cellular adaptation in the extremophilic red microalga Galdieria sulphuraria 074W.
Why it matters for Grey Muzzles
Underlines how deeply Galdieria's biology is shaped by its ability to survive extreme environments.
GaldieriaCellular Resilience - Preclinical Research · 2022 · Plants
Sulfur Starvation in Extremophilic Microalga Galdieria sulphuraria
G. Salbitani et al.
Summary
Reports biological effects of sulphur deprivation in Galdieria sulphuraria cultures.
Why it matters for Grey Muzzles
Relevant to understanding Galdieria's rich sulphur biology and its natural sulphur-containing compounds.
GaldieriaSulphur Amino Acids - Published Literature · 2018 · Frontiers in Nutrition
Astaxanthin in Exercise Metabolism, Performance and Recovery: A Review
D. R. Brown et al.
Summary
Review of astaxanthin in exercise metabolism, performance and recovery research.
Why it matters for Grey Muzzles
Broader context for why astaxanthin is interesting in the ageing and recovery conversation.
AstaxanthinExercise RecoveryOxidative Balance - Emerging Research · 2026 · Nutrients
The Effects of Astaxanthin Supplementation on Exercise Metabolism, Performance and Recovery
S. Liu et al.
Summary
Recent review discussing evidence around astaxanthin supplementation, biomarkers of muscle damage, soreness and recovery.
Why it matters for Grey Muzzles
Keeps our position on astaxanthin honest: research is promising but remains context-dependent.
AstaxanthinExercise Recovery - Mechanistic Evidence · 2022
Phycocyanin: Anti-inflammatory effect and mechanism
R. Liu et al.
Summary
Mechanism-focused publication discussing phycocyanin's antioxidant and anti-inflammatory mechanisms.
Why it matters for Grey Muzzles
Deepens the mechanistic understanding behind one of Galdieria's most studied compounds.
C-PhycocyaninOxidative Balance - Emerging Research · 2024
The production and characteristics of glycogen synthesized by Galdieria strains
A. P. Kristijarti et al.
Summary
Research on production and properties of glycogen in Galdieria strains.
Why it matters for Grey Muzzles
Adds to the picture of Galdieria as a next-generation functional carbohydrate source.
GaldieriaIngredient Characterisation
One daily treat. A serious ingredient platform.
The treat is only the vehicle. What matters is the ingredient system behind it, formulated for daily use across the pathways of canine healthy ageing.