As most UV filter substances approved for usage in sunscreens have reactive carbonyl groups, the possibility of their reaction with amino groups of proteins or free amino acids of the human skin cannot be precluded. An initial screening on high performance thin layer chromatography (HPTLC) amino plates showed that benzophenones and dibenzoylmethanes were strongly bound to the amino phase after heating and/or UV irradiation, while camphor derivatives were less reactive. To understand the underlying mechanisms and to identify reaction products, the reactions of benzo­phenone-3 (BP‑3), dibenzoylmethane (DBM), 4-t-butyl-4’-methoxydibenzoyl­methane (BM‑DBM), hydroxymethylbenzoyl sulfonic acid (HMBS), 3‑benzylidene camphor (3‑BC), and 4‑methyl­benzylidene camphor (4‑MBC) in the presence of butyl amine or ethanolamine as protein models were studied. Heating the reaction batches transformed BP-3 and HMBS into benzophenone imines with high yields, while DBM and BM‑DBM afforded enamines and, due to α-clevages, acetophenone and benzamide derivatives. An additional UV irradiation of the reaction batches affected the product distribution in the cases of BM‑DBM and DBM, but not for BP‑3 and HMBS. The amine reactions generally had great influence on the UV absorption spectra. For both BP-3 and HMBS, a significant bathochromic shift together with increased absorbance was observed, thus an increased UVA protection, while the dibenzoylmethanes clearly lost UVA efficiency. According to the slight binding to the HPTLC amino layer, 3‑BC and 4‑MBC did not yield any reaction product with butylamine or ethanolamine.