Tobacco heaters, electronic (e)-cigarettes, hookahs and cannabis are very popular with young people, but are these products really safe? Tobacco heaters or "vaporizers" have a comparable addictive potential to tobacco cigarettes due to a similar nicotine and tobacco content. They usually contain smaller amounts of other, but no less harmful alkadienes and aromatic hydrocarbons, but also carcinogenic acenaphtene 295% higher than tobacco cigarettes. With the newer e-cigarettes, sweetish fruit flavors overlay the bitter tobacco taste, so that young never-smokers are won as a new target group. 90% of all e-cigarette consumers use tobacco cigarettes at the same time instead of stopping smoking. In addition to carcinogenic heavy metals, formaldehyde can be detected in the vapor of almost all e-cigarettes, including nicotine-free ones. In e-cigarettes with a high voltage, the formaldehyde content is increased 5 times. Healthy, asthmatic and COPD patients show bronchial obstruction after e-cigarette use. The lung disease caused by a vitamin E acetate in e-cigarette vapor affected 2,807 patients with 68 deaths. In the smoke from a water pipe, the content of nicotine, carbon monoxide and formaldehyde is significantly higher than in a cigarette. Heavy metals are inhaled more deeply due to the cooler smoke, which increases the risk of cancer. Memory disorders, increased rates of schizophrenia, worsening of asthma and COPD are described as long-term effects of cannabis consumption. When inhaled, the same toxins and carcinogens are detected as with tobacco cigarettes. In summary, although the new products are popular, they cannot be recommended for smoking cessation or as a safe alternative.