Why Do Two Serums With the Same Ingredient Give Different Results?

Two serums can contain the same active ingredient—and even show the same percentage on the label. Yet, it can behave differently on skin because the finished formula is more than just its hero ingredient. Concentration, pH, stability, delivery system, vehicle, supporting ingredients and packaging, too, can all influence how a serum feels, remains stable and performs.

In this dermatologist-approved blog, we help you understand how one serum with the same ingredient can work differently, explain how serum formulations work and how to pick the right serum formulation for you.

Why Doesn't the Ingredient List Tell the Whole Story?

Looking at an ingredient list these days is like reading a chemistry label. They have a lot of information regarding what's in the product, but what they miss is pH levels, how ingredients interact, how they are delivered to your skin, and how they may feel on it. 

Ingredient concentration

• ratios between ingredients

• solvent/vehicle

• pH levels

• supporting ingredients

• delivery system

• stabilizers

• texture modifiers

An ingredient list is merely a list of parts, not the entire recipe. All these factors can end up contributing to and deciding how a serum formulation acts on your specific skin. 

Does the Percentage of an Active Tell You How Effective a Serum Is?

People often assume the higher the concentration, the more effective the serum is going to be. But this is far from the truth. Higher percentages do not mean better results. Nor do they tell you how effective a serum is going to be. More often than not, that  will tell you how irritating it may be for your skin.

• Skin tolerance matters

• How suitable it is for your specific skin type matters 

• Formulation stability matters 

How Does ph Change How a Serum Performs?

When you apply your serum, its pH levels dictate whether it’ll peacefully absorb into your skin, how aggressive it may be, or if it even completely neutralises before it can be effective for your skin. 

Why Does Serum Stability Matter?

According to the European Journal of Cardiovascular Medicine, the stability of active ingredients like Vitamin C, Retinol, etc, are important to ensure that the active ingredient does not breakdown when exposed to heat, oxygen and light. Without stability, a serum loses its potency, changes colour and making the active ingredient lose its effectiveness, rendering the serum useless and unsafe to use. 

Vitamin C is the clearest example

Pure Vitamin C or L-Ascorbic Acid, is highly unstable. When exposed to heat, light and air, it oxidises rapidly, losing its benefits. Some skincare formulations, like deconstruct, have 3-0 ethyl ascorbic acid, which is a more stable derivative vs other vitamin c derivatives,  along with ferulic acid to boost stability and antioxidant protection. 

What Is a Serum's Delivery System?

How an active ingredient is delivered into your skin is the delivery system in a serum. Certain formulations have advanced delivery systems, such as Liposomal Technology,  that bypass your skin barrier and help deliver the ingredient directly into your skin and how the entire formulation behaves on your skin. 

If you’re wondering how liposomal technology works, liposomal technology works by wrapping the active ingredient into microscopic bubbles called liposomes. They mimic your skin’s cells which makes it super easy for them to blend in, to deliver the active ingredient deep into your skin for it to work best. 

Why Can Two Serums With the Same 10% Ingredient Feel Completely Different?

The active ingredient makes up only a fraction of your serum. The remaining base or vehicle, dictates the texture, absorption and overall skin feel. This is why two serums of the same concentration offer two different experiences for two different people.   Here’s what else that can contribute to why a serum can feel one way for one person, and a whole different way for another:

• Skin type 

• Skin conditions 

• Routine 

• Skin tolerance

• consistency

• Other products or actives 

• Individual formulation variation

Here’s what makes a good serum 

concentration + stability + delivery + tolerability + formulation

Does Packaging Affect Serum Performance?

This is something you don’t usually factor in when deciding your serum but yes, packaging is one of the most critical factors that can affect how your serum performs. 

Why? 

• Oxidisation: for ingredients like vitamin c, which oxidise easily under exposure to heat, oxygen and air, standard dropper bottles expose the serum to them with every time you open them, reducing its potency. 

• Photodegradation: UV and visible light degrade the active. When serums are stored in a clear glass bottle, light penetrates it, destroying the active before you apply. 

• Contamination: you may accidentally contaminate the formula with your hands, when it comes to drippers. When its back in the bottle, it’ll introduce bacteria which can harm the product 

How Deconstruct Uses Formulation Beyond the Ingredient List

Deconstruct's recent serum reformulations focus not only on active concentration but also on

• Stability 

• Delivery of the ingredient  

• Texture and feel of the serum 

• How the formula behaves in a routine, especially when layering

Deconstruct has specifically focused on serum upgrades in terms of formulation and delivery rather than simply increasing active percentages.

A great example of this is Deconstruct’s Vitamin C serum with Liposomal Technology.

Powered by Liposomal technology, Deconstruct’s Vitamin C serum helps in targeted delivery of the active deep into your skin to protect your skin and the active, rather than having it sit on your skin’s surface and evaporate. 

Apart from delivery, their serum focuses on 

• Stability: With 0.5 ferulic acid to boost stability, and using 3-0 ethyl ascorbic acid, which is a more stable derivative of vitamin C, the overall formula offers higher stability

• Formula and texture: Watery-base and lightweight formula to maintain skin comfort with a Non drying and non-sticky texture. 

• Calming and barrier supporting ingredients: Like 0.5% centella extract to help calm skin and 0.25%panthenol to help soothe skin

What Should You Compare When Choosing Between Two Similar Serums?

The Final Verdict

If you’re wondering why one serum works one way with you, but another with the same concentration works differently for another, the truth is,the active is only as good as the entire formulation system supporting it. The active is only a fraction of a serum.There’s more to a serum than chasing the highest concentration of the active. Look for the texture, stability of the formula, as well as the delivery technology. That’s where the true efficacy of a serum lies. In it’s entire formulation recipe. Choose smart, stable and lightweight formulas over the loudest concentrations.