We can safely say that bath bombs are the most Insta-friendly skin care products out there, and by now you’ve probably seen loads of bathtub selfies with multicolored waters and candle-lit backdrops. But what are bath bombs really made of and what benefits of bath bombs have made them irresistible to so many of us?

Bath bombs are single-use, spherical blends of smoothing, fragrant extracts and oils that you can toss in your tub before bath time. The primary ingredients are sodium bicarbonate and citric acid, which interact with each other once dissolved in water to create that fizzing effect we know and love. Once this reaction occurs, the bath bomb dissolves and breaks apart, releasing all the good stuff inside: from delicious scents to skin smoothing emollients, which act as softeners on your skin.