Stability testing cosmetics is an important step in the manufacturer of products to ensure that the end result is something that is effective and safe. Well formulated and stable treatments are not only safe and effective, they are also much more pleasant to use. Like many of you, I’ve purchased cosmetics that separate, or start to smell badly just a short period after opening. It’s possible that the manufacturer of these products may not have tested them adequately to ensure their stability under certain conditions.


Stability testing for cosmetics is a complicated process that involves 3 main tests:

  1. Physical and Chemical Integrity Tests. Evaluate color, odor/fragrance, pH value, viscosity, texture, flow, and emulsion stability (signs of separation)
  2. Microbiological Stability Tests. Evaluate the degree of contamination with bacteria, mold, and yeast.
  3. Packaging Stability Tests. Evaluate the impact of packaging on the contained product.

How To Stability Test

Companies can do stability testing for cosmetics in real time or under ‘accelerated’ conditions, which aim to speed up the results of real time. Most companies perform tests using “Accelerated” Conditions. The actual tests involved vary depending on the product, its packaging and its anticipated shipping, storage, display and use. The following tests may be conducted:

  • High Temperature Testing: High temperature testing is commonly used as a predictor of long-term stability. Storage and stability at a range of high temperatures (between 37 and 45oC) is a good predictor as to how long a product will maintain its integrity.
  • Cycle Testing: Often called a freeze-thaw cycle, the product is frozen and thawed three times testing a range of temperatures from below freezing to high room temperature.
  • Centrifuge Testing: Centrifuging is the process of rapidly rotating a product to force its contents (typically fluids) to separate out.
  • Light Testing: Formulas and packaging can be sensitive to UV radiation. Light testing helps to predict if the product or packaging will discolor in its chosen container.
  • Mechanical Shock Testing: As products are transported, shipping movements may damage them. Vibration testing can help to determine if this will happen. Products should also be monitored for changes in color, odor/fragrance, viscosity and pH value.

Microbiological stability tests assess microbial contamination either during the production and filling or during the use of the cosmetic by the consumer. These tests are very important to ensure that the treatment is safe and maintains its quality. In particular, we are concerned about dangerous bacteria.

Finally, cosmetics should also be tested to be stable in the container in which they are packaged.

The topic of stability testing for cosmetics sounds like a boring one. Yet, it is a complex process and an important one too. For your health and safety it’s imperative that the cosmetics you are using have gone through these widely recognized standard tests.


★ Reviews

Let customers speak for us

61 reviews
Grapefruit Ginger Natural Deodorant Roll-On
Mellisa Herlache (Suamico, US)
Didn’t work for me.

I couldn’t get past the scent of the Grapefruit Ginger deodorant. It’s definitely not detox- I’ve been exclusively using natural deodorant for almost 2 years. However, customer service was amazing. They reached out to me and refunded me my purchase cost. Really wish it would’ve worked for me but worth a try for others, especially since they stand by their satisfaction guarantee.

Dear Mellisa,

We're so sorry to hear that our deodorant doesn't work for you. All Apothekari products come with 100% money-back guarantee. Someone from our customer service team will be in touch to help resolve this issue.

Customer Service

Bespoke Vitamin C 15% Serum
Allison H. (North Vancouver, CA)
Nice glow

I use it every other day and have no sensitivity issues with this product. A lot of other products can give me acne if they're too thick/creamy or they bother my skin if they have a strong perfume scent. The only downside is it can be hard to use up before the expiry date, but I have learned to keep half the bottle in the fridge to make it last a bit longer. I will keep buying this product in the future.

A is for Anti-Aging Retinal Serum
Lisa Pelzer (Mexico City, MX)
Very satisfied

I was never able to use a retinal cream before. My skin was just too sensitive. This is a really nice product 👍🏻

Ageless Skin Set
Alana (Vancouver, CA)
Simply the BEST

The BEST skincare line I have ever used. My skin has never looked or felt this good. Thank you 😊

Love it

First healthy deodorant I’ve tried that actually works for me…and no rash. Thank you for developing this awesome product.

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