Street heroin is often cut with various additives. Hence it is difficult to know the actual contents or purity of a street deal of heroin. This lasts about half an hour and gives way to three to four hours of lethargy. Heroin reduces pain, hunger and libido and slows breathing and pulse rate. Heavier doses cause a feeling of warmth and sleepiness.
Heavy doses can also lead to nausea and vomiting.
Overdoses can cause respiratory failure and death. Long-term heavy use of heroin can lead to a loss of appetite and sex drive, sexual dysfunction, pneumonia and constipation. Pure heroin is relatively non-toxic but is very addictive. Psychological and physical dependence are common results of long-term use and can lead to financial, dietary, lifestyle and health problems. Additives in street heroin can cause health problems including collapsed veins, abscesses and tetanus and even damage to the brain and internal organs.