Five-year results are reported of a controlled long-term comparative study to assess the effects of ergoloid mesylates (1.5 mg 3-times daily) and placebo on medical, psychological and electrophysiological variables. Initially, 148 healthy elderly volunteers of both sexes were included. Eighty-nine subjects (48 on ergoloid mesylates and 41 on placebo) are still in the double-blind study; 39 subjects have left the trial for various reasons (6 deaths, 25 drop-outs due to disease, and 8 withdrawals) and 20 subjects are participating under 'open' conditions. Formal statistical comparison of the two groups in terms of 10 medical and psychometric outcome variables did not produce significant differences. However, a number of relevant findings and trends with regard to the effects of ergoloid mesylates were established: the drug was well tolerated objectively and subjectively; subjective complaints such as frequent dizziness, cardiac symptoms and leg cramps were improved; there was less increase than on placebo in the number of subjects with pathological ECG findings; there was less increase than on placebo in the number of subjects taking digitalis; fewer subjects than in the placebo group had an increase in the number of major diagnoses; the decrease in some lipid fractions was more pronounced than on placebo; and performance in some psychometric tests (WAIS Vocabulary, WAIS Performance) was better in the ergoloid mesylates group. None of these findings, by itself, would be evidence of a dramatic effect of ergoloid mesylates on the participants in the double-blind trial. Taken together, however, they fall into a pattern, suggesting that ergoloid mesylates was partly effective in maintaining physical and mental health in these healthy elderly individuals. The finding of more disease-related and symptom-related drop-outs in the placebo group (25 vs. 20 in the ergoloid mesylates group) supports this assumption. Furthermore, the fact that a number of subjects who had left the double-blind trial for medical reasons improved on subsequent ergoloid mesylates administration may be seen as a further argument in favour of a prophylactic effect of ergoloid mesylates on pathological concomitants of ageing.