Non-steroidal anti-inflammatory drugs (NSAIDs) are indicated for treatment of rheumatoid arthritis and osteoarthritis, but often induce gastric adverse experiences (AE), including gastric ulcers and complications. Inhibitors of proton pump and H(2) antagonists are very effective for duodenal ulcer; meanwhile, cytoprotective drugs are more effective for gastric ulcer. D-002 is a mixture of higher aliphatic alcohols obtained from beeswax, wherein triacontanol is the most abundant. D-002 induces anti-ulcer effects through a cytoprotective mechanism, being more effective in protecting against ethanol- and NSAID-induced ulcers. The present double-blind, placebo-controlled clinical study was undertaken to investigate the effects of D-002 on gastric symptoms associated to piroxicam use on patients suffering osteoarthritis. Fifty-nine patients, all taking piroxicam, 20 mg/day, were randomized to placebo or D-002 (40 or 100 mg/day) for 14 days. The primary efficacy variable was the reduction on the frequency of patients with gastric AE compared with placebo. Pain evolution was investigated to discard any influence on D-002 on the analgesic effect of piroxicam. The frequency of patients treated with D-002, 40 and 100 mg/day, reporting acidity [0 of 18 (0%) and 1 of 21 (4.8%), respectively] was lower (P < .05) than in placebo [6 of 20 (30%)]. Also, the frequency of patients treated with 100 mg/day reporting some gastric AE [5 of 21 (23.8%)] was lower (P < .05) than in placebo [13 of 20 (65.0%)]. The analgesic effect of piroxicam was unaffected with D-002. Treatment was well tolerated. Two patients discontinued from the study because of gastrointestinal AE: one in the placebo group and the other treated with D-002, 40 mg/day. Other three patients discontinued because of other AE: mildly uncontrolled hypertension (one in the placebo group, one treated with D-002, 40 mg/day) and headache (one treated with D-200, 100 mg/day). It is concluded that D-002 could be useful for controlling gastric AE of patients treated with NSAIDs, although further studies with a larger sample size and longer follow-up are needed for definitive conclusions.