First of all, introduce the ways to take the main drugs:

No.4 (Heroin)-absorbed by the lungs after nasal inhalation, injection and heating.

Coke-can be injected or absorbed by the lungs after heating; Coke also has a kind of nasal powder, which can be eaten like K.

K powder-inhaled or dissolved in water and drinks.

Magu, ice-can be heated, inhaled, absorbed by the lungs, and even injected with high-purity ice (it seems that only Japan and South Korea have it).

Marijuana-smoking or special marijuana pipe (the latter only applies to marijuana paste)

Yaokou

LSD- is contained in the mouth or attached to any part of the body with pores and absorbed by the capillary wall.

Morphine-administered by injection or heating.

The main drug that can be inhaled is K powder, No.4, and the drug source of Infernal Affairs is the "Golden Triangle", so it should be heroin.

New drugs mainly act on people's central system and directly on people's brain, thus achieving the illusion effect, which is different from traditional drugs. Most traditional drugs first act on human endocrine, such as dopamine, and produce sedative or excitatory effects by improving and reducing endocrine feedback to human brain. Traditional medicine brings people quiet or excitement, but it is not an uncontrollable illusion.

But the same thing, when you inhale them, you won't feel uncomfortable or uncomfortable. Because drugs are so powerful, when you inhale, hallucinations have already occurred.