When a stretch mark cream says “clinically tested,” what does that actually mean?
For moms, this question matters because they have already heard a lot of promises about stretch mark creams. Many still wonder if these creams for stretch marks actually work, or if stretch marks are mostly genetic anyway.
Stretch marks are not just lines on the skin. They can come with rough texture, unevenness, dullness, and changes in how belly skin looks and feels.
Why Moms Need More Than Promises
In a Momcozy user research of 552 pregnancy and postpartum discussions, stretch marks were the most mentioned belly skin concern, appearing in 50.4% of the valid sample. But moms were not only talking about lines. They also talked about itching, tightness, dryness, rough texture, and whether belly creams were worth using every day.
The hesitation is understandable. In the same research, 47.6% of product complaints were about stretch mark products “not working,” and 31.7% were about products feeling too expensive or like a waste of money. Many moms also know stretch marks can be influenced by genetics.
That is why Momcozy wanted to go beyond another claim. We wanted to test the product in a structured way and show what changed through both skin measurements and real user feedback.
So for Momcozy Pro-Collagen Belly Firming Moisturizer, our Momcozy belly cream and Momcozy stretch mark cream, we wanted to look at two things.
What changed on the skin?
And did moms actually feel those changes?
That is why this 8-week test included both instrumental analysis and consumer perception testing — making it one of the more thorough clinical tests for a stretch mark cream available today.
What Is Clinical Testing in Skincare?
There are two common ways to test the visible effects of a skincare product or beauty device.
The first is instrumental analysis. This means using professional skin testing devices to measure visible or textural changes in the skin. Research on cosmetic efficacy testing notes that non-invasive skin measurement tools are often used to evaluate skin conditions such as surface contour, mechanical properties, wrinkles, pigmentation, and texture. Instrumental testing helps turn visible changes into measurable data.
The second is consumer perception testing. This focuses on what participants notice after using the product. Does the skin feel smoother? Does it look better? Is the product easy to absorb? These are subjective responses, but they matter because skincare is something people use in real life, not only in a lab.
Momcozy used both.
We looked at the data.
We also listened to the moms.
What Were the Results?
After 8 weeks of twice-daily use, the test showed visible and measurable improvements in the stretch mark area.
We focused on the changes moms usually care about most: whether the marks looked less obvious, whether the skin felt smoother, and whether the belly area looked and felt more firm and elastic.
Key Instrumental Results
- Stretch mark depth decreased by 33.33%
- Skin firmness improved by 42.26%
- Skin elasticity increased by 25.26%
- Skin glossiness increased by 57.01%
- Skin smoothness-related parameter improved by 30.02%
These results show that the test did not only look at whether stretch marks appeared lighter by eye. It measured changes in the skin itself, including depth, texture, firmness, elasticity, and overall appearance.
This matters because stretch marks are not only about color. They can also look uneven, feel rough, or make the skin look less smooth. By measuring these different areas, the test gave a clearer picture of how the stretch mark area changed over time.
What Participants Reported
After 8 weeks:
- 100% agreed their abdominal skin looked more aesthetic
- 100% agreed the color of stretch marks looked lighter
- 100% agreed the skin at the stretch mark area felt smoother
- 97% agreed skin felt firmer and more elastic
- 97% agreed the product felt refreshing and easy to absorb
- 100% were satisfied with the overall effect
This part matters just as much as the instrument data.
A product can show numbers on a report, but moms still need to feel the difference in daily life. It should feel comfortable on the skin. It should absorb well. It should be easy enough to use morning and night.
That is why we looked at both sides: what the tools measured, and what moms actually noticed after using the product.
Who Took Part in the Study?
The test recruited 35 participants. In the end, 33 participants completed the study and were included in the final analysis.
The participants were adult women between 28 and 45 years old. The average age was 36.42 ± 4.37 years old.
The inclusion criteria focused on women who had stretch marks within one year after the end of lactation. The tested skin area also showed concerns such as looseness, lack of firmness, rough texture, dullness, or lack of glossiness.
How the Product Was Used
Participants used Momcozy Pro-Collagen Belly Firming Moisturizer, a topical cream for stretch marks, on the abdominal stretch mark area.
The routine was simple. After cleaning and drying the abdomen, participants applied the stretch mark cream evenly to the stretch mark area and gently massaged until absorbed.
The product was used twice a day, once in the morning and once in the evening.
The test also recorded actual product usage. Among the 33 participants who completed the study, the average usage amount was 153.21g by Week 4 and 353.40g by Week 8.
In other words, these results were measured after consistent daily use, not after one application.
Participants returned to the lab at Week 0, Week 4, and Week 8 for measurement. Before each test, they cleaned the abdominal skin and sat quietly for 30 minutes in a controlled room. This helped reduce the effect of outside conditions on the results.
What We Measured and How
The test followed a clear sequence.
Participants first had the abdominal area photographed with a digital camera. Then a technician evaluated the visible level of stretch marks. After that, the stretch mark area was measured with professional skin analysis tools, including Antera 3D, VC20, Colorimeter, Glossymeter, and Cutometer. At the final visit, participants also completed a self-assessment questionnaire.
Antera 3D was one of the key tools used in the test. It is a professional skin imaging system used to analyze and measure skin features such as wrinkles, texture, pigmentation, redness, and other visible skin changes.
In simple words, the test looked at the skin in two ways: what professional tools could measure, and what moms could actually see and feel after using the stretch mark cream.
Why This Matters for Moms
Clinical testing is not only about numbers on a report.
It helps us understand whether a stretch mark cream can respond to what moms actually care about in daily life. Do stretch marks look lighter? Does skin feel smoother? Does it feel more elastic? Does the rough texture feel less obvious when moms touch their belly skin?
For Momcozy, that matters.
Pregnancy and postpartum change the body in many ways. Belly skin may stretch, feel tight, look uneven, or carry marks that remind moms of everything their bodies have been through. We know those changes can feel personal. So we did not want to rely on a simple promise or a pretty product claim.
That is why we looked at both sides.
We looked at the instrumental data.
We also listened to the moms who used the product.
The devices helped us measure visible and textural changes. The participants helped us understand how those changes felt in real life. Both are important, because skincare is not only about what can be measured in a lab. It is also about whether a mom feels more comfortable caring for her changing skin every day.
Momcozy does not only care about what a device can measure. We care about how moms feel when they touch their skin, get dressed, and take a quiet moment to care for themselves.
That is why we believe in combining science with warmth. The goal is not to make skincare sound magical. The goal is to make results clearer, care more practical, and support deeper comfort for moms’ changing skin.
References
- Momcozy. Reddit Pregnancy Belly Care Needs User Research Report [Internal report]. Analysis of 552 valid Reddit samples from 37 pregnancy and postpartum communities; data period 2024 Dec–2025 May.
- Intertek Testing Services Shenzhen Ltd. Guangzhou Branch. Test Report: Pro-Collagen Belly Firming Moisturizer. Report No. GZCRS-2025-LT-01. 2025 Dec 11. Internal test report.
- Takahashi M. Non-invasive Methods for Efficacy Test of Cosmetic Products by Examining the Skin Physiological Conditions [Internet]. Journal of Society of Cosmetic Chemists of Japan; 2017 [cited 2026 May 21]. Available from: https://www.jstage.jst.go.jp/article/sccj/51/2/51_105/_article/-char/en
- Piérard GE. Instrumental Non-invasive Assessments of Cosmetic Efficacy [Internet]. Journal of Cosmetic Dermatology; 2002 [cited 2026 May 21]. Available from: https://orbi.uliege.be/bitstream/2268/9700/1/INSTRUMENTAL.pdf
- Miravex Limited. Antera 3D for Dermatology & Aesthetics [Internet]. Miravex; [cited 2026 May 21]. Available from: https://miravex.com/dermatology-aesthetics/
