In-Vivo

In Vivo Sunscreen Testing: The Gold Standard for Efficacy and Claim Substantiation

In vivo sunscreen testing represents the definitive "final exam" for a sun care product, providing conclusive, real-world evidence of its performance on human skin. This clinical methodology is universally recognised as the gold standard for validating efficacy. Regulatory authorities across the globe, including the U.S. Food and Drug Administration (FDA) and bodies governed by the International Organization for Standardization (ISO), mandate in vivo data to substantiate primary sun protection claims, such as the Sun Protection Factor (SPF). For a brand to legally and confidently make specific, quantifiable sunscreen efficacy claims on its packaging, in vivo trials are non-negotiable. This transforms a marketing promise into scientifically defensible proof, making it an essential investment in product certainty and regulatory compliance.

Our In Vivo Testing Methodology: Adherence to Global S style="color: #ed7e12; text-decoration: none;" tandards

A high-stakes clinical trial demands absolute precision. Our photobiology testing methodology is built on strict adherence to the most current global standards, ensuring every variable is controlled to produce the most accurate and reliable data possible.

• Test Subject Selection: We select test subjects based on objective colorimetric measurements, such as the Individual Typology Angle (ITA°), to ensure a standardised range of skin tones appropriate for SPF testing. This quantitative approach reduces subjectivity and enhances the reproducibility of results across studies.
• Solar Simulation & Calibration: Our clinical facilities use high-precision Xenon Arc solar simulators that closely replicate the spectral output of natural sunlight. These instruments are calibrated to ensure uniform UV energy delivery across the exposure field, consistent with the requirements of both ISO 24444 and FDA methodologies.
• Standardised Application & Exposure Procedure: The test product is applied by trained technicians at a controlled dose, followed by a defined drying period before UV exposure. A series of sub-sites is then irradiated with incremental UV doses to determine protection performance under standardised conditions.
• Erythema Assessment (MED Determination): Erythema (skin redness) is assessed by trained evaluators to establish the Minimal Erythemal Dose (MED) for both treated and untreated skin areas. The SPF value is calculated from the ratio of these MEDs, following principles common to both ISO and FDA SPF determination procedures.
  
  

Comprehensive In Vivo Testing Services

We offer an extensive suite of in vivo and in vitro photobiology testing services to substantiate all key performance, safety, and differentiating claims for sun care and related products.

Core In Vivo Efficacy Tests

SPF Determination (ISO 24444)
The gold-standard in vivo method for validating primary UVB protection claims and product labelling.

UVA Protection Factor (UVAPF) Assessment (ISO 24442)
This in vivo test evaluates Persistent Pigment Darkening (PPD) to determine UVA protection levels and PA ratings (e.g., PA++++), as required in markets such as Japan and other Asian regions.

Water Resistance Testing (ISO 16217 & ISO 18861)
Confirms “Water Resistant” (40 min) and “Very Water Resistant” (80 min) label claims using standardised water immersion protocols conducted alongside SPF testing.AS/NZS Water Resistance testing is also available to support label claims for the Australian and New Zealand markets.

Phototoxicity & Photoallergy Testing
For products or ingredients that absorb UV light, in vivo safety testing (including photopatch protocols) determines potential photoirritant or photoallergic responses, ensuring consumer safety and regulatory compliance.

Advanced & Specialised Claim Substantiation

Cosmetic Elegance and Sensory Attributes
Includes quantitative “White Cast Score,” which combines objective colourimeter data (L* value) with subjective panel evaluations across multiple skin tones, providing measurable data on cosmetic acceptability.

Additional In-Vivo Claim Tests

• Sand resistance
• Towel friction resistance
• Salt or chlorinated water exposure (skin/hair)
• Sunscreen remanence (residual film durability)
• Soothing and freshness effects
• Tan preparation, accelerator, and extension efficacy
• Overall product efficacy under real-use conditions
  
  

Complementary In Vitro & Laboratory-Based Tests

In Vitro Water Resistance Screening Test
Assesses UV protection retention following water immersion using a laboratory substrate. This serves as a fast, cost-effective pre-screen of formulation performance before in vivo confirmation.

IR-A Protection Testing
Evaluates product protection against infrared-A–induced skin damage through:

• Biometric approach: skin colour, temperature, and microcirculation measurements
• Biochemical approach: oxidative stress and enzyme assays (SQOOH, MDA, CAT, SOD)

HEV (Blue Light) Protection
Determines how effectively a formulation shields skin from high-energy visible (blue) light exposure, associated with pigmentation and oxidative stress.

UPF (Fabric Testing)
Assesses UV-blocking capacity of textiles, providing a certified UPF rating for sun-protective clothing and accessories.

Understanding and Leveraging Your In Vivo Test Results

Our service extends beyond the clinic. We deliver a comprehensive final report that is more than just a number. It is a robust, submission-ready document containing raw data, detailed statistical analysis, and a clear interpretation of the results. This documentation provides the scientifically sound evidence needed to substantiate your on-pack marketing claims, populate your product's technical file, and build a compelling, data-driven story for consumers and regulatory bodies alike.

The In Vivo Testing Process: A Step-by-Step Guide

We provide a transparent, structured process to guide you from project initiation to the final report.

• Consultation & Protocol Design: We begin by collaborating with you to understand your product, target markets, and specific claim objectives to design the optimal study protocol.
• Subject Recruitment: We recruit qualified volunteers who meet the specific criteria for the study, including the required skin type range as determined by ITA∘ measurements.
• Product Application & Exposure: In our controlled clinical environment, trained technicians apply the product and expose test sites to precisely calibrated doses of UV radiation from our solar simulators.
• Erythema/PPD Assessment: Following the 16-24 hour incubation period, our expert evaluators assess the skin's response to determine the MED or PPD endpoint.
• Data Analysis & Reporting: Our biostatisticians analyze the data, and we compile a comprehensive report detailing the methodology, results, and conclusions of the study.

Regulatory Compliance Support

Our expertise in global standards ensures the data we provide is formatted and presented to meet the specific requirements of major regulatory bodies worldwide.

• US FDA: Data to support compliance with the OTC Drug Monograph (M020).
• European Union: Documentation for the Cosmetic Product Safety Report (CPSR) under Regulation (EC) No 1223/2009.
• Australia/New Zealand: Testing in accordance with AS/NZS 2604:2021 for TGA compliance.
• Asia (Japan/South Korea): Data for quasi-drug or functional cosmetic submissions.
  
  

Frequently Asked Questions about In Vivo Testing

Q1. Is in vivo SPF testing safe for volunteers?

Absolutely. All our clinical studies are conducted under strict ethical guidelines and require approval from an Institutional Review Board (IRB) or ethics committee. The UV doses used are minimal and controlled to elicit only a faint, temporary reddening of the skin.

Q2. How many subjects are required for an in VIVO SPF test?

Standard international protocols, such as ISO 24444, typically require a panel of 10 to 20 qualified subjects to ensure the results are statistically valid.

Q3. My in vitro test gave me SPF 40, but my in vivo result was SPF 15. Why?

Discrepancies can occur because in vitro tests cannot fully replicate the complex interactions between a formula and human skin, such as how the product forms a film or interacts with the skin's topography. In vitro results are highly predictive for R&D, but the in vivo results are the definitive measure of real-world performance.

Q4. Can you test on a diverse range of skin tones?

Yes. We are committed to inclusive testing and have extensive experience conducting studies on a diverse range of skin phototypes. Our use of the ITA∘ standard ensures we can objectively recruit and test on the specific skin tones relevant to your target consumer base.

Q5. What are the benefits of in vivo testing for sunscreen products?

In vivo testing provides real-world evidence of sunscreen efficacy on human skin, making it the gold standard for validating SPF and water resistance claims. Unlike in vitro testing, which is useful for initial screenings, in vivo testing ensures that your product's performance is accurately represented in real-world conditions. This level of rigor is crucial for regulatory compliance and allows you to make defensible claims about your product’s effectiveness against UV radiation and water resistance.

Q6. How does in vivo testing for water resistance work?

In vivo testing for water resistance ensures that your sunscreen maintains its SPF effectiveness after exposure to water. It is essential for sunscreens marketed as "water-resistant" or "very water-resistant." The tests are conducted under controlled conditions using standardised protocols:

• 40-minute water resistance: According to ISO 16217.
• 80-minute water resistance: According to ISO 18861.

These tests involve immersing participants in water and assessing the sunscreen's efficacy, ensuring it remains effective after sweat or water exposure.

These tests provide solid evidence that your sunscreen will perform as claimed in real-world conditions, enhancing your product's marketability.

Q7. What skin types are considered in your in vivo SPF testing?

For in vivo SPF testing, it is critical to test on a diverse range of skin tones to ensure that the sunscreen performs across different skin phototypes. At Eurofins CRL, we use the Individual Typology Angle (ITA°) to select test subjects based on their skin colour, ensuring that our study includes participants with a variety of skin tones relevant to the target market.

This inclusive approach ensures that your product can make reliable claims across different demographics and is compliant with global testing standards.

By conducting studies on diverse skin types, we ensure the accuracy and reliability of your sunscreen's performance across various populations.

Get Started with In Vivo Testing

Validate your product's final efficacy with the industry's gold standard. Contact us to schedule a consultation with our clinical testing experts.