In Vivo vs. In Vitro Testing in Skincare: What the Labels Don't Tell You

From miracle serums to age-defying creams, skincare marketing is full of big promises. But how can you make sure what you’re buying is more than just fancy words? Well, that’s where product testing comes in. But here’s the catch: not all testing is created equal. Today, we’re peeling back the layers–literally–to look at the science behind those asterisks and ‘clinically tested’ product claims.

The terms in vitro and in vivo often appear on skincare labels, but do you know what they really mean? More importantly, how do they help you tell science-backed skincare from just clever marketing?  Understanding the difference between in vitro and in vivo testing is key. Let’s break down the science and read between the lines to find out what’s worth your time (and your skin).

Spoiler alert: Only one of these is a true stamp of approval. And at Novology, we invest in the right kind of testing to bring you products that don’t just talk the talk, but also walk the walk.

Read on to find out which one!

In Vitro VS In Vivo: Key Differences

1. Definition

In Vitro

An in vitro study is a type of scientific study or clinical trial conducted in a controlled laboratory setting. The term "in vitro" means "in glass" in Latin, referring to the fact that these experiments are carried out in test tubes or petri dishes rather than on or within living organisms. By removing cells or tissues from their natural environment, researchers can observe specific biological reactions without interference from the organism's other components. This allows for a clearer understanding of cellular interactions.

In Vivo

In contrast, an in vivo study (Latin for "in the living") involves experiments performed on whole living organisms, such as animals or humans. Unlike in vitro studies, this method allows scientists to observe how particular products or treatments interact with the entire organism, offering a clearer picture of overall body reactions and broader health impacts. 

2. Environment

In Vitro

In vitro testing is conducted on isolated cells or tissues in petri dishes or test tubes. This is done under highly controlled laboratory conditions that minimise the influence of any external biological processes of the organism from where these cells come. 

In Vivo 

Generally following in vitro testing, in vivo studies transition research from petri dishes to living systems, and is carried out on whole organisms. It typically includes testing on animals or humans. It's all about seeing how the product or treatment works once it's put into a living, breathing body, where everything is connected and things can become unpredictable, unlike the carefully controlled environment of a lab. 

3. Purpose

In Vitro

In vitro testing is done to observe how particular treatments or products interact at a cellular or molecular level, without the interference of the other bodily processes of the organism. It provides valuable preliminary data on safety and effectiveness, helping scientists minimise risks when progressing to in vivo testing.

It's like tasting a sauce on its own before adding it to the main dish. This way, you know exactly what adjustments to make and can avoid the risk of messing up the whole dish.

In Vivo

In vivo testing, on the other hand, is done with the purpose of getting a more complete understanding of how treatments or products affect the entire body.

It's like finally adding that sauce to your finished dish. It’s only when it all comes together that you can tell if the flavours complement each other or if something feels off.

4. Scale & Time

In Vitro

In vitro testing is typically conducted on a smaller scale and is often faster than in vivo studies. This efficiency stems from its simpler setup and the absence of ethical concerns associated with testing on living organisms. By using isolated cells or tissues, researchers can quickly gather initial data without the risks and complexities involved in whole-animal or human studies. 

In Vivo 

Since in vivo testing involves humans or animals, it requires careful ethical considerations, specifically concerning animal welfare and informed consent for human trials. Which is why such studies tend to be more complex, time-consuming, and resource-heavy than lab-based alternatives.

5. Accuracy / Reliability

In Vitro

In vitro studies provide crucial insights, but they tell only part of the story. However, these isolated tests can't capture the full complexity of living systems. These tests are done outside the complex system of a whole organism, so they might miss important biological interactions that only occur in real life. This means that while in vitro results are valuable, they may not accurately translate to how the product affects real people or animals. 

In Vivo

In vivo testing looks at how entire living organisms respond to treatments or products. This gives us information that cell-based studies alone can't provide. By observing whole-body reactions, in vivo testing offers a more reliable prediction of product safety and effectiveness in real life. 

Think of in vitro as testing your driving skills on a simulator with controlled settings, and in vivo as driving on a busy road during rush hour. You might ace the simulator, but the actual road—with its traffic, aggressive drivers, unpredictable potholes, and pedestrians—offers a much clearer and more reliable measure of your driving skills.

6. Regulatory Acceptance

In Vitro

In vitro testing is normally done in the early stages of product development. It helps identify and eliminate potentially harmful or ineffective ingredients before moving on to more complex stages of testing. It gives researchers crucial but limited insights, which are valuable for preliminary assessments, but not sufficient for regulatory approval.

In Vivo

Skincare products require in vivo testing to meet regulatory approval standards. It's the difference between predicting how a car performs on paper and actually taking it for a test drive. In vivo results show how products interact with living, breathing humans—not just with cells in a petri dish. Regulatory bodies typically require in vivo data to demonstrate the safety and efficacy of skincare products in real-world conditions. When it comes to product claims, in vivo trials are the difference between "trust us" and "here's proof."

Real-World Examples of In Vitro and In Vivo Testing

In Vitro Testing

For example, a skincare brand aims to develop a new moisturizer using an innovative compound. Before testing on humans, they need to ensure it won't cause skin irritation. To do this safely, they turn to in vitro testing using human skin cells. These cells, called keratinocytes, act as stand-ins for real human skin. Scientists apply the new compound to these cells and carefully observe any signs of irritation or damage. This approach allows the company to identify potentially harmful ingredients early on, without risking human or animal subjects. It is a way to test-drive the product at a cellular level, making sure it's gentle and effective before it ever touches a person's skin.

In Vivo Testing

The moisturizer has passed the lab tests with flying colors. Great start, but now it's time for the real test—on actual human skin. This is where in vivo testing comes in. The skincare company invites a diverse group of volunteers with different skin types to use the moisturizer as part of their daily routine, while researchers keep a close eye on how their skin reacts. Are there any rashes? Allergic reactions? Does it actually hydrate skin? This real-world trial helps catch any issues that might have slipped through the cracks in the lab. It's like a final exam for the moisturizer, making sure it's not just safe but also does what it promises before it hits the shelves.

And that’s exactly the approach we take with all our products. Take our Acne Rescue Spot Corrector, for example—it has been through intensive in vitro and in vivo testing to ensure an acne solution that works for your skin, not against it.

In Vitro VS In Vivo: The Final Verdict

In vitro testing is the warm-up lap, but in vivo? That's the grand prix. While in vitro testing provides valuable initial insights, in Vivo testing ultimately takes the crown in skincare product development. In vitro methods screen ingredients safely, but in vivo testing provides conclusive results. It offers real-world evidence of product performance on human skin under various conditions, capturing nuances lab tests might miss. Ultimately, in vivo testing determines a product's safety and efficacy, ensuring skincare innovations are both effective and safe for consumers.

At Novology, we believe that innovation only matters if it’s backed by proof. That’s why every product undergoes six months of rigorous human clinical trials to ensure our patented ingredients deliver real-world results. And with the approval of top dermatologists, you can count on skincare that’s more than just skin-deep. When we make a claim, you know it’s backed by real, proven results.