The Clinical Pharmacology Institute of the Zhejiang University, Hangzhou, 310009, China ;To further reveal the risks of heroin abuse to human body, and to determine the injuries of oxidation, peroxidation and lipoperoxidation induced by nitric oxide and other free radicals to heroin abusers, we determined and compared plasma values of lipoperoxides (LPO), nitric oxide (NO), vitamin C (VC), vitamin E (VE), β carotene (β CAR) and erythrocyte values of LPO, superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSH Px) in 114 heroin abusers and 100 healthy volunteers. Using linear regression and correlation as well as stepwise regression and correlation, we also analyzed the effect of the abusing duration, and daily abusing quantity on the above mentioned biochemical parameters in the heroin abusers. The results showed that, compared with the healthy volunteer groups, the average plasma values of LPO, and NO, and the average erythrocyte value of LPO in the heroin abuser group were significantly increased ( P <0.0001), and the average plasma values of VC, VE, and β CAR and the average erythrocyte values of SOD, CAT, and GSH Px were significantly decreased ( P <0.0001). Analysis of linear regression and correlation showed that with prolonged heroin abusing and with increased daily quantity in the heroin abusers, the plasma values of LPO, and NO, and the erythrocyte value of LPO were gradually increased ( P< 0.001), whereas the plasma values of VC, VE, and β CAR and the erythrocyte values of SOD, CAT, and GSH Px were gradually decreased ( P <0.001). Analysis of stepwise regression and correlation indicated that the plasma values of NO, VC and VE were closely correlated with the abusing duration and daily abusing quantity. These results indicate that the balance between oxidation and antioxidation in the heroin abusers was seriously disturbed, and the injuries induced by nitric oxide and other free radicals, through oxidation, peroxidation and lipoperoxidation to the bodies of heroin abusers exacerbated. It is therefore necessary that in abstaining from heroin dependence, the heroin abusers should acquire sufficient quantities of antioxidants such as VC, VE and β CAR. The Clinical Pharmacology Institute of the Zhejiang University, Hangzhou, 310009, China ; To further reveal the risks of heroin abuse to human body, and to determine the injuries of oxidation, peroxidation and lipoperoxidation induced by nitric oxide and other free radicals to heroin abusers, determined and compared plasma values ​​of lipoperoxides (LPO), nitric oxide (NO), vitamin C (vitamin E), vitamin E (VE), beta carotene (beta CAR) and erythrocytes values ​​of LPO, superoxide dismutase catalase (CAT), and glutathione peroxidase (GSH Px) in 114 heroin abusers and 100 healthy volunteers. Using linear regression and correlation as well as stepwise regression and correlation, we also analyzed the effect of the abusing duration, and daily abusing quantity on the the above mentioned biochemical parameters in the heroin abusers. The results showed that, compared with the healthy volunteer groups, the average plasma values ​​of LPO, and NO, and the average erythrocyte value of LPO in the heroi The average plasma values ​​of VC, VE, and β CAR and the average erythrocyte values ​​of SOD, CAT, and GSH Px were significantly decreased (P <0.0001). Analysis of linear regression and correlation showed that with prolaily heroin abusing and with increased daily quantity in the heroin abusers, the plasma values ​​of LPO, and NO, and the erythrocyte value of LPO were gradually increased (P <0.001) VE and β CAR and the erythrocyte values ​​of SOD, CAT, and GSH Px were gradually decreased (P <0.001). Analysis of stepwise regression and correlation indicated that the plasma values ​​of NO, VC and VE were correlated with the abusing duration These results indicate that the balance between oxidation and antioxidation in the heroin abusers was seriously disturbed, and the injuries induced by nitric oxide and other free radicals, through oxidation, perox idation and lipoperoxidation to the bodies of heroin abusers exacerbated. It is therefore necessary that in abstaining from heroin dependence, the heroin abusers should acquire adequate quantities of antioxidants such as VC, VE and β CAR.