The teeth whitening procedure holds an important place in the routine work of dental practitioners even though its safety is questioned by some of them, the major concern being the possibility of demineralization of the hard teeth tissues. The objective of the present study was to measure the hydrogen ion concentration in seven commercial professional take-home teeth whitening gel kits with the use of custom-made trays. The study was based at the Department of Biological Chemistry of the Moscow State Medical Stomatological University. The following professional teeth whitening systems for home use were investigated: Day White containing 9.5% hydrogen peroxide, Night White containing 16% or 22% carbamide peroxide, Opalescence PF containing 10%, 15% and 22% carbamide peroxide, Belagel’ O containing 20% carbamide peroxide gel. The results of the study indicate that the hydrogen ion concentration in the professional teeth whitening gels for home use exerts no appreciable influence on the release of the mineral components from the hard tissues of the teeth. The pH values in the investigated teeth whitening gels varied from 7 to 10 corresponding to the neutral to alkaline range.