[bgutierrez]

> One reason the practice hasn’t been more widespread is that it delivers a diminished dose of a drug. It isn’t clear how much of a high secondary users receive, and some medical experts say there is no more than a placebo effect.

Yes, this makes sense. People are not actually getting high from this, so I doubt that very many people are trying to get high from injecting other people's blood directly.

> Unusual injection practices in Pakistan include selling half-used, blood-infused heroin syringes. (link to https://pubmed.ncbi.nlm.nih.gov/19558668/)

This is the headline, I think. Street vendors sell hits of a syringe that may have already been stuck in someone else. Every time the needle enters a blood vessel, some of the blood goes back into the needle. It's not that users are asking for "blood-infused" syringes, it's that the vendors are sticking multiple people with a single syringe and now 50% of intravenous drug users in Sargodha have HIV.

[EA-3167]

That sounds far more realistic than some macabre attempt to transfuse. Just from a purely skeptical point of view, drug users want to get high, and it's more effective to split a dose in two separate shots than it is to recycle someone's blood. Never mind the issue of blood type aside, from a pure drug-seeking behavior angle it makes no sense.

[Ylpertnodi]

> Just from a purely skeptical point of view, drug users want to get high,

Many use drugs for pain relief, too.

[parineum]

Many use drugs for allergies as well.

[sva_]

I think you misunderstood the study in Pakistan.

> The injector injects 3 ml and keeps 2 ml (the scale) as injection fee.

Heroin users will first inject the drug, then immediately draw blood back into the syringe and then reinject that, to accomplish a kind of mixing the drug with the blood in the syringe. The study claims that people leave some of that blood/drug mix in the syringe as a fee.