Can you get high if someone touches weed and then you shake their hand and then you eat something with that same hand?

It is highly unlikely that you would get high from the scenario you described, where someone touches weed, you shake their hand, and then you eat something with that same hand.

Here are the key points to consider:

1. THC Transfer: Tetrahydrocannabinol (THC), the psychoactive compound in marijuana, is not easily transferred through skin contact. THC is primarily absorbed through the lungs when smoked, or through the digestive system when ingested, not through casual skin contact34.

2. Amount of THC: Even if a small amount of THC were to be transferred to your hand, it would be extremely minimal and not sufficient to cause any psychoactive effects when ingested4.

3. Secondhand Exposure: Studies on secondhand marijuana smoke indicate that even inhaling significant amounts of secondhand smoke in poorly ventilated areas is unlikely to result in a substantial high, and certainly not through indirect skin contact and subsequent ingestion34.

Therefore, the risk of getting high from this scenario is virtually nonexistent.