While making a spa face mask at home is generally safe, there are some potential risks and side effects to be aware of. Always patch test new ingredients before using them on your face to avoid allergic reactions. Avoid using ingredients that are known irritants, like peppermint or cinnamon, and be careful not to overdo it with exfoliants like sugar or salt, which can damage your skin. If you experience any redness, itching, or burning during or after using a mask, discontinue use and consult a dermatologist.