Injecting into an area that has become firm: why not to

Injecting into an area that has become firm: why not to Writing it up because I had to work it out twice and would rather nobody else did.

Asking about the failure mode rather than the procedure, because the procedure is documented and the failure mode is not.

I know what I am supposed to do. What I do not know is what it looks like when it has gone wrong, and by the time something is obviously wrong it is usually too late to learn from it.

So: what does the early version of this mistake look like, and what would you check first?

This follows the opening post rather than contradicting it.

The single most common technique error described here is drawing to the wrong graduation because the barrel was read at an angle. Read it straight on, at eye level, every time.

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.

That holds under the stated conditions and I have stated them.

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.

Same conclusion as the reply above, reached differently, which is mildly reassuring.

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.

That has been true for the cases I have seen and I have not seen many.

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.

I had written a reply contradicting post #5 and deleted it. Here is what survived.

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.

If it helps: the failure mode here is usually boring rather than dramatic.

Post #5 describes the usual case. This is about the unusual one.

Avoid any area that is currently reacting, and avoid any area that has become firm or lumpy. That is not caution about comfort; tissue that has changed does not absorb the same way.

If that reads as pedantic, it is, and it has saved me twice.

Sensible. I would want the same detail before I acted on it either.

The arithmetic in post #9 is right; the assumption feeding it is the part to check.

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.

It cost nothing to check and would have cost something not to.

Answering the question post #8 raises rather than the one it answers.

A site rotation scheme that actually works: abdomen, outer thigh, back of arm, outer hip. Rotate through them in order, move a minimum 2 cm between consecutive sites, note the site with each dose. If a local reaction appears you have the history. If you rotate properly you will not get lipohypertrophy from overuse of one area.

This is the sort of thing that ought to be settled and apparently is not.

Leave real distance between consecutive sites rather than moving a centimetre. Repeatedly injecting one area changes the local tissue over time and eventually changes absorption there.

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.

Two sources, same conclusion, and I could not rule out that one copied the other.