BACKGROUND: Intravascular low-level laser irradiation (ILLLI) therapy with He-Ne laser can effectively inhibit the occurrence of heroin withdrawal syndrome, but the therapeutic effect should be evaluated by quantitative standards.OBJECTIVE: To evaluate the effect of intravascular low-level He-Ne laser irradiation against withdrawal syndrome with intravenous according to the criteria proposed by the authors.DESIGN: Randomized controlled trial in heroin-addicted patients.SETTING: Analysis and Testing Laboratory of Xinxiang Medical College and Center of Laser Medical Research of Zhenzhou University Medical CollegePARTICIPANTS: The study was completed in Center of Laser Medical Research in Zhengzhou University in January 2003. Thirty heroin addicts from the Detoxification Center of Zhengzhou including 25 male and 5 female patients aged 19- 45 years were divided randomly into experimental group and control group with 15 cases in each. The patients' history of drug abuse ranged from 0. 5 to 5 years and the daily doses they took was 1.0-4.0 g.INTERVENTIONS: Patients in the experimental group were treated by ILLLI therapy after hospitalization. The therapy was administered once daily for 60 minutes in each session, for a total of 10 days for a treatment course. The irradiating power of the laser was 2.0-3.0 mW with a power density of 7.07-10.6 mW/mm2. Patients in the control group were treated with conventional therapy with algidon combined with buprenorphine hydrochloride. The 12 main symptoms(vomiting, goose pimples, sweating, agitation, shaking, lacrimation, nasal congestion, insomnia, abdominal pain,body temperature changes, muscular pain, and heart rate changes) were scored for 0, 1, 2, and 3 corresponding to absent, mild, moderate, and severe symptoms, with the total score of 36.MAIN OUTCOME MEASURES: Comparison of the scores for the withdrawal symptoms between the two groups.RESULTS: The 30 cases were all available for result analysis. The scores of vomiting, insomnia, agitation, shaking, goose pimples and abdominal pain in the experimental group were 2.0±0.5, 2.5±0.4,4.6±0.3,3.6±0.7,3.1±0.3 and 5.7±0.6 respectively, which were obviously lower than those in control group(5.1±0.7,6.0±0.7,7.4±0.6, 7.1±0.6,5.7±0.6 and 6.4 ±0.7 respectively, t =9.90-16. 81, P＜0.01).CONCLUSION: Intravascular low-level He-Ne laser irradiation can effectively relieve heroin withdrawal syndrome.