RETINDUO® Technology: Dual technology, triple innovation in advanced retinoid science

The dermatological science behind ENDOCARE RENEWAL Retinoid Serums

Retinoids (vitamin A derivatives) are widely recognised as the gold standard in dermatology for improving visible signs of skin ageing, including wrinkles, uneven pigmentation, rough texture and loss of firmness.^1-4

How retinoids work in the skin

Retinoids work at a cellular level by converting in the skin into retinoic acid, the biologically active form.

Retinoic acid binds to specific receptors in skin cells, regulating gene expression to^5,6:

• Accelerate epidermal renewal
• Stimulate collagen synthesis
• Improve skin texture and radiance
• Reduce the appearance of fine lines

This receptor-driven signalling helps skin behave more like younger, healthier skin.

Retinol vs Retinal: Understanding two essential retinoids

Retinol and retinal (retinaldehyde) are two of the most important vitamin A derivatives used in skincare.

• Retinol acts as a storage and transport form of vitamin A, gradually converting into retinoic acid.⁷
• Retinal converts more directly into retinoic acid, making it faster-acting.

Within the skin, retinoids follow this pathway:

Retinol ⇄ Retinal → Retinoic Acid

Retinoic acid is the biologically active form that regulates gene expression involved in skin renewal and collagen production.^8,9

Retinal also contributes efficiently to retinoic acid formation and plays a key role in supporting epidermal renewal.^10,11

Combining retinol and retinal allows formulations to support multiple pathways of vitamin A metabolism, improving both efficacy and tolerability. This combination with enhanced delivery mechanisms and bioavailability boosters is the scientific rationale behind RETINDUO®.

What is RETINDUO® Technology?

RETINDUO® is an advanced retinoid delivery system developed by Cantabria Labs, designed to optimise both performance and skin tolerability.

Dual Technology – Triple Innovation

• Encapsulated Pure Retinol - Uses microsponge technology for gradual release and sustained activity
• Encapsulated Retinal with AOX Technology - Supports enhanced, controlled delivery with improved tolerability
• Natural Bioavailability Boosters - Help optimise retinoid activity within the skin

This triple innovation supports visible skin renewal while maintaining skin comfort.

ENDOCARE RENEWAL Retinoid Serums explained

ENDOCARE is a science-led anti-ageing skincare range from Cantabria Labs, formulated to improve skin barrier function, radiance and renewal.

ENDOCARE RENEWAL Retinoid Serums are the latest innovation in the Renewal category with two progressive potency levels:

ENDOCARE RENEWAL Retinoid Serum (RETINDUO® Potency Level 1)

• Ideal for early signs of ageing
• Suitable for sensitive skin
• Perfect for retinoid beginners

ENDOCARE RENEWAL Retinoid Intensive Serum (RETINDUO® Potency Level 2)

• Supports intensified skin renewal
• Designed to address more advanced signs of ageing
• Suitable for experienced retinoid users / those stepping up from tolerated use of ENDOCARE RENEWAL Retinoid Serum

Key features and ingredients across both formulations

• Cross-linked hyaluronic acid for hydration
• Niacinamide 4% to support the skin barrier
• Airless packaging to maintain stability and potency

Clinical evidence behind RETINDUO®

RETINDUO® has been shown in ex vivo studies to help aged skin regain characteristics of younger, healthier skin.¹²

In photoaged skin models, RETINDUO® (Level 2) significantly increased, collagen, elastin and epidermal thickness in just 10 days.

Clinically proven results: ENDOCARE RENEWAL Retinoid Intensive Serum

A controlled clinical study demonstrated significant improvements in key skin parameters when used with a progressive retinisation protocol including¹³:

• Reduced appearance of wrinkles (4 weeks)
• Improved skin firmness (4 weeks)
• Increased hydration (4 weeks)
• Enhanced elasticity (8 weeks)
• Improved epidermal renewal (12 weeks)

Before and after 12 weeks using ENDOCARE RENEWAL Retinoid Intensive Serum using the dermatologist recommended retinisation programme:

What is a Retinisation Protocol?

A retinisation protocol is a structured approach to introducing retinoids to minimise irritation and maximise results.

Recommended 3-Phase Approach

Phase 1: Initiation (Weeks 1–2)

• Apply twice weekly (evenings)

Phase 2: Build-Up (Weeks 3–4)

• Apply every other night

Phase 3: Optimisation (Weeks 5–8)

• Apply nightly as tolerated

Why daily sun protection is essential when using retinoids

Using a retinoid serum can significantly improve skin renewal, but it also increases the skin’s sensitivity to UV radiation. This makes daily sun protection a critical step in any retinoid skincare routine.

HELIOCARE provides advanced broad-spectrum SPF 50+ protection, helping to defend the skin against UVA and UVB rays, visible light and infrared-A radiation.

How to choose the right ENDOCARE Retinoid Serum

• ENDOCARE RENEWAL Retinoid Serum: Positioned as the first step in the ENDOCARE retinisation process. Use if you are new to retinoids or have sensitive skin.
• ENDOCARE RENEWAL Retinoid Intensive Serum: The second step in the ENDOCARE retinisation process. Use if your skin is already acclimatised to Retinoids and you are looking for more intensified skin renewal.

Always follow a gradual retinisation protocol for best results and tolerability.

Frequently asked questions about retinoids

What do retinoids do for the skin?

Retinoids increase cell turnover and stimulate collagen production, improving wrinkles, texture and pigmentation.

How long do retinoids take to work?

Visible improvements can begin in 4 weeks, with optimal results typically seen after 8–12 weeks.

Can sensitive skin use retinoids?

Yes. Using a gradual retinisation protocol and well-formulated products can improve tolerability.

Why is sunscreen important with retinoids?

Retinoids increase epidermal turnover which can increase the skin’s sensitivity to UV radiation. Daily use of broad-spectrum SPF 50 sunscreen is essential.