Cloudy Vitamin C Serum: Cause and Solution

Based on the information provided:

• Yes, the cloudy Vitamin C serum is still usable.
• The cloudiness occurred because the serum was poured into a bottle with leftover LipidSoft. LipidSoft is an oil, and although the original formula contained Laureth-23 as an emulsifier, there wasn't enough to properly emulsify the additional oil. This caused the oil droplets dispersed in the water-based serum to become larger, which refracts light and makes the serum appear cloudy.
• To address this, you can simply shake the bottle well before each use. This is the recommended method.
• Alternatively, you could gently warm the serum and add more Laureth-23 until it becomes clear. However, using too much Laureth-23 might potentially clog pores, so shaking before use is generally preferred.
• It's good that you chose the shaking method for personal use.