# Sunscreen Scam: In-Vitro vs In-Vivo Testing — What Really Matters for SPF Accuracy

**By Bhavana Doshi** · 2025-10-24

## **Sunscreen Truth: In-Vitro vs In-Vivo Testing — What Really Matters for SPF Accuracy**

In the past few weeks, conversations around **sunscreen testing methods** have created quite a stir online. Many people are confused between _in-vitro_ and _in-vivo_ SPF tests — and influencers are debating which one is “real.”  
As a skincare formulator and founder of **Pure Bubbles Skincare**, I’d like to share a balanced perspective grounded in both science and experience.

### **Understanding In-Vitro vs In-Vivo SPF Testing**

**In-Vitro Testing** (ISO 24443):  
This is a **non-human test method** performed in the lab, under controlled conditions. It studies how UV filters behave when spread on artificial substrates that mimic skin. These tests are recognized under the **COLIPA standard**, which is accepted globally and used to determine UVA protection factors and SPF ratings before human trials.

**In-Vivo Testing:**  
This is the **gold standard**, conducted directly on human skin to evaluate how the sunscreen performs under real-world conditions. However, in-vivo testing is expensive, time-consuming, and often restricted in countries where animal or human testing regulations are strict.

Both methods are credible. In-vitro testing gives reliable insights into **UV filter performance, photo-stability, and SPF consistency**, while in-vivo testing confirms final results on skin.

### **Why This Debate Matters for Indian Sunscreens**

In India, **sunscreen standards and grading systems** are still evolving. Brands that voluntarily conduct ISO 24443-based testing at **government-accredited labs** are actually going above what’s legally required.  
So when a founder invests lakhs of rupees into independent lab testing, it isn’t for marketing — it’s for **transparency and education**.  
As someone who formulates and personally studies sunscreen chemistry, I deeply respect such efforts.

### **The Hard Truth About High-SPF, Lightweight Sunscreens**

At **Pure Bubbles**, we once worked for almost **two years** on a potential **SPF 60 sunscreen**.  
Here’s what I learned first-hand:  
High SPF = **heavier film**.  
No matter how advanced the filters are — whether old-generation or new-generation UV filters — they are **oil-miscible molecules**. As SPF levels rise, the concentration of these filters increases, which makes the texture **thicker and creamier**, not airy or gel-like.

That’s why when a sunscreen claims to be _ultra-lightweight, invisible, matte, and SPF 60+_, I always say — _be curious_. The math of formulation chemistry doesn’t change: **true protection often feels substantial.**

### **What Real Protection Feels Like**

Personally, I don’t mind if a sunscreen leaves a slight **white cast** or feels a bit **goopy** — because that’s what often ensures genuine UV protection.  
Those slightly thicker, old-school textures are the ones that truly protect **sensitive skin**, reduce **hyperpigmentation**, and prevent **photo-aging**.  
Sunscreen isn’t makeup; it’s **skin medicine**.

### **The Way Forward for Skincare in India**

This debate shouldn’t divide the skincare community. Instead, it should spark better **consumer awareness**, **clearer SPF labeling**, and **standardized testing regulations** in India.  
We need more founders, chemists, and educators to share their learnings — not just influencers and viral trends.

At Pure Bubbles, our goal has always been simple: to help you make **informed, mindful skincare choices** that respect both science and skin integrity.

Let’s keep this discussion about education, not accusation. 🌞

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> Source: [Pure Bubbles Skincare](https://purebubblesskincare.com/blogs/pure-bubbles-skincare/sunscreen-scam-in-vitro-vs-in-vivo-testing-what-really-matters-for-spf-accuracy)