Ethyl Cyanoacrylate – The main bonding agent responsible for quick-drying and long-lasting hold.
Carbon Black – Gives the adhesive its deep black color and helps it blend with lash lines for a seamless look. (Not used in clear adhesives.)
PMMA (Polymethyl Methacrylate) – Adds flexibility and strength to the adhesive bond.
Hydroquinone – Acts as a stabilizer to prevent premature polymerization (helps preserve shelf life).
Formaldehyde (trace) – Sometimes found in very low residual amounts as a byproduct of cyanoacrylate production. (High-quality medical-grade adhesives are typically labeled formaldehyde-free.)