Yes, glycerol (or glycerin) is generally halal. Glycerol is considered halal if it is derived from plant sources such as palm oil or soybean. However, if it is derived from animals, its halal status depends on the slaughter methods and potential contamination. If the glycerol’s source is unspecified, it is permissible to use if no alternative is available due to the principle of umumul balwa (general difficulty). Most glycerol used today is plant-based and therefore halal.

Sources:

• IslamQA
• IslamQA
• Echemi

And Allah knows best.