Angle of injection and whether 90 degrees is always right — the long version

The opening post answers the question as asked. The question underneath it is different.

A new needle for each injection is not fussiness. A needle blunts on first use and a blunted needle is the reason the second injection hurts more than the first.

This is the version I would want a new member to read first.

Post #5 is right about the mechanism and I think understates the practical bit.

If you have to inject at a different time of day than usual, that is a much smaller perturbation than it feels for a weekly compound with a week-long half-life.

The rule of thumb is fine; the edge cases are where it earns its keep.

Rotate on a fixed sequence rather than choosing each week. A sequence you follow beats a scheme you improvise, and it produces a record you can read back.

Everything in post #25 holds. The case it does not cover is the one I have.

Alcohol swabbing and letting the site dry is the whole of the preparation for a subcutaneous injection into intact skin. Injecting before it dries is what stings.

Post #36 answers the question as asked. The question underneath it is different.

An honest declaration on Angle of injection: I have a prior here and it is strong enough that you should weight what I say downward. Stating it rather than hiding it.

Pinching a fold is useful for lean tissue and unnecessary elsewhere. The point is to keep the needle out of muscle, and whether you need to depends on the site and on you.

Post #48 and I disagree about the size of the effect, not about the direction.

If you have to inject at a different time of day than usual, that is a much smaller perturbation than it feels for a weekly compound with a week-long half-life.

Worth separating two things that post #52 runs together.

The reason Angle of injection is hard to answer is that the obvious measurement and the relevant quantity are not the same thing, and substituting one for the other is silent.