OBJECTIVES The objective of this thesis is a review and critical discussion of new pieces of knowledge about fibroblast and collagen degenerative changes as a key mechanism of chronological ageing and photoageing. Special emphasis was given to the cosmeceuticals and formulations which are being used or tested for prevention and/or slowing down of such degenerative changes. MATERIALS AND METHODS Literature search was conducted electronically with PubMed being the database searched. During the research of the literature the answers to the specific questions related to the problems of this thesis were searched. The literature was researched from the general articles to the specialized articles and the articles relevant for this thesis were selected. RESULTS A major feature of aged skin is fragmentation of the dermal collagen matrix and this fragmetation is acceleraated by sunlight. The collagen network is organized and maintained by dynamic mechanical tension provided by the fibroblasts responsible for its production. Age related reduction of mechanical tension is a critical driving force for molecular changes that underlie the appearance of aged skin. Although there exists a multitude of cosmeceuticals that are claimed to improve appearance of chronologically/photoaged skin only few have been rigorously evaluated and their mechanism of action elucidated. CONCLUSION Amongst various antiaging agents retinoids are the most promising agents that are available for the treatment of aging dermis. Emerging agents are also peptides that stimulate fibroblast activity and induce collagen production. However the efficacy of topically applied cosmeceuticals is restricted by their permeation to the site of their action. The approach to improve the dermal bioavailability of cosmeceuticals depends on their physicochemical properties of and may include: (i) modification of the molecule in order to improve its lipophilicity and/or stability (ii) incorporation of absorbtion enhancers in the formulation (iii) and the encapsulation of cosmeceutical into different nanocarriers.