The Two Shelf Lives of Skincare Products — What You Should Know
- Navneet Kaur
- 1 hour ago
- 3 min read
Most people are familiar with the expiry date printed on cosmetic products — but that’s only half the story.
In skincare, there’s something equally important called Period After Opening (PAO). It’s not just a technical term — it can make the difference between a product that performs well and one that causes irritation, spoilage, or poor results.
Whether you’re a dermatologist, formulator, distributor, or part of the wider skincare industry, understanding both shelf lives helps you make informed decisions for your customers and your brand.
🧴 Shelf Life #1: Expiry Date
This is what’s commonly printed on the label — the date until which a sealed, unopened product will remain safe and effective, if stored properly.
It’s also called the Date of Minimum Durability (DMD). This is based on lab testing under controlled conditions and is regulated by authorities in most countries.
⏳ Shelf Life #2: Period After Opening (PAO)
PAO tells you how long a product is safe to use after it has been opened.
You’ll often see this on international products marked as a little open jar icon with “6M” or “12M,” meaning the product should ideally be used within 6 or 12 months of opening.
🧪 Why PAO Matters
Once opened, a product is exposed to air, light, moisture, fingers, and the environment. These can all affect:
Microbial safety (risk of contamination)
Chemical stability (breakdown of ingredients like vitamin C or retinol)
Physical changes (texture, smell, color)
A product that’s completely stable in its sealed form may still spoil quickly once opened — especially in hot and humid regions like India.
🔬 What Determines a Product’s PAO?
At Velite, we look at several factors when formulating and testing skincare products. These include:
1. Water Content (a_w)
Products with more water are more prone to microbial growth.
2. pH Level
A very low or high pH can naturally inhibit microbial growth.
3. Packaging Design
Airless pumps offer more protection than jars.
Opaque containers block damaging light.
Tight-sealing caps help reduce oxidation and contamination.
4. Preservation Strategy
We evaluate how preservatives perform under real use, not just in controlled lab tests.
5. Ingredients
Some actives, like vitamin C, retinol, and botanical extracts, are sensitive to light, air, or heat and can break down quickly if not properly protected.
🌡️ Climate Makes a Big Difference
India falls under WHO’s Zone IVb – hot and very humid (30°C / 75% RH). This climate accelerates both microbial growth and chemical degradation.
That’s why skincare products designed for this region need extra attention when it comes to formulation, packaging, and stability testing.
🧠 How PAO Is Determined
While PAO isn't printed on all products, brands and manufacturers often use internal testing and simulations to estimate it. This typically involves:
Risk scoring based on product formulation and packaging
Lab testing for microbes and chemical changes
In-use simulations (e.g., opening, dosing, exposure to light, etc.)
Real-world temperature and humidity stress tests
This process helps manufacturers build better products and provide accurate guidance for safe usage.
💡 What Consumers Can Do
Even if a product doesn’t list a PAO, users can follow best practices to extend product life:
Store below 30°C in a dry place
Keep the cap tightly closed
Avoid dipping fingers directly into jars — use a spatula
Stop using if the color, texture, or smell changes
Use consistently after opening, rather than letting it sit unused
🎯 Final Thoughts
In modern skincare, shelf life is about more than just an expiry date. The true performance of a product depends heavily on how it behaves after opening — especially in real-life conditions.
At Velite, we believe PAO is not something to guess — it’s something to engineer. Through rigorous testing, smart packaging choices, and science-based formulation, we aim to ensure that skincare remains safe, stable, and effective, even after opening.
تعليقات