pH and Stability Testing in Skincare OEM: Verifying a Formula Holds Up Over Time

Skincare formulas change over time — color can shift, separation can occur, and pH can drift, which affects both safety and skin compatibility. pH and stability testing puts a formula through temperature and time to verify it stays stable, safe, and effective through its shelf life.

The Scenario: Three challenges in stability

Stability testing faces three challenges:

Pain Points

• Formulas can shift color, separate, or drift in pH over months;
• pH drift changes how the product interacts with skin and how actives behave;
• Temperature extremes in shipping and storage can reveal hidden instability.

The Solution: Three stability solutions

Stability testing offers three solutions:

1. Accelerated aging Cycle the formula through temperature extremes to reveal instability early.

2. pH monitoring Track pH over time to confirm it holds in the skin-compatible range.

3. Appearance and separation checks Verify color, odor, and texture stay consistent across the test.

The Result: A formula proven stable

With these tests, the formula is proven to hold up through its shelf life. Stability testing turns a good formula into a reliable product.