Versus

Wella EIMI Thermal Image Heat Protection Spray Versus Schwarzkopf Professional Osis+ Flatliner

Heat Protectant
Heat Protectant
German Brand Germany
German Brand Germany

Updated on September 22, 2025

Overview

What they are

These products are both cruelty-free heat protectants. They have a total of 3 ingredients in common

Suited For

They're both likely to be good for dry skin, brightening skin and scar healing

Free From

They both do not contain any parabens or sulfates

What's Inside

They both contain harsh alcohols, fragrances and silicones

We independently verify ingredients, and our claims are backed by peer-reviewed research. Spot a product that needs an update? Let us know.

Ingredient Info

Click any item below to learn more and see relevant ingredients

What's inside

What's inside

At a glance

Click on any of the items below to learn more

Key Ingredients

Benefits

Concerns

Ingredients Explained

These ingredients are found in both products.

Ingredients higher up in an ingredient list are typically present in a larger amount.

Antimicrobial, Astringent, Masking

Alcohol Denat. is an alcohol with a denaturant property. It is created by mixing ethanol with other additives.

This ingredient gets a bad rep because it is irritating and drying - mostly due to its astringent property. Astringents draw out natural oils in tissue, constricting pores and leaving your skin dried out.

However, alcohol denat. is not all that bad.

Due to its low molecular weight, alcohol denat. tends to evaporate quickly. One study on pig skin found half of applied alcohol evaporated in 10 seconds and less than 3% stayed on skin.

This also helps other ingredients become better absorbed upon application.

Studies are conflicted about whether this ingredient causes skin dehydration. One study from 2005 found adding emollients to propanol-based sanitizer decreased skin dryness and irritation. Another study found irritation only occurs if your skin is already damaged.

Small amounts of alcohol are generally tolerated by oily skin or people who live in humid environments.

The rule of thumb is if this alcohol is near the end of an ingredients list, it will probably not affect your skin much.

Also...

This ingredient has antimicrobial and solvent properties.

The antimicrobial property helps preserve products and increase their shelf life. As a solvent, it helps dissolve other ingredients.

Other types of astringent alcohols include:

Learn more about Alcohol Denat.
Buffering, Humectant, Skin Conditioning

Lactic Acid is another well-loved alpha hydroxy acid (AHA). It is gentler than glycolic acid but still highly effective.

Its main role is to exfoliate the surface of the skin by loosening the “glue” that holds dead skin cells together. Shedding those old cells leads to smoother, softer, and more even-toned skin.

Because lactic acid molecules are larger than glycolic acid, they don’t penetrate as deeply. This means they’re less likely to sting or irritate, making it a great choice for beginners or those with sensitive skin.

Like glycolic acid, it can:

Lactic acid also acts as a humectant (like hyaluronic acid). It can draw water into the skin to improve hydration and also plays a role in the skin's natural moisturizing factor (NMF) in the form of sodium lactate.

Studies show it can boost ceramide production to strengthen the skin barrier and even help balance the skin’s microbiome.

To get results, choose products with a pH between 3-4.

Lower strengths (5-12%) focus on surface exfoliation; higher strengths (12% and up) can reach deeper in the dermis (deeper, supportive layer) to improve skin texture and firmness over time.

Though it was originally derived from milk, most modern lactic acid used in skincare is vegan. It is made through non-dairy fermentation to create a bio-identical and stable form suitable for all formulations.

Legend has it that Cleopatra used to bathe in sour milk to help reduce wrinkles.

Lactic acid is truly a gentle multitasker: it exfoliates, hydrates, strengthens, and brightens. It's a great ingredient for giving your skin a smooth, glowing, and healthy look without the harshness of stronger acids.

Read more about some other popular AHA's here:

Learn more about Lactic Acid
Skin Conditioning, Solvent

Water. It's the most common cosmetic ingredient of all. You'll usually see it at the top of ingredient lists, meaning that it makes up the largest part of the product.

So why is it so popular? Water most often acts as a solvent - this means that it helps dissolve other ingredients into the formulation.

You'll also recognize water as that liquid we all need to stay alive. If you see this, drink a glass of water. Stay hydrated!

Learn more about Water

When to use

2 Routines
50% use in am
50% use in pm
100% use every day
3 Routines
67% use in am
33% use in pm
67% use every as_needed

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