Devices · Syringes & needles · continued

[2026 update] 0.3 mL versus 0.5 mL versus 1 mL barrels: resolution matters posts 121–125

Devices › Syringes & needles dead volume needle gauge & length subcutaneous injection Solved

This is a continuation of a long topic, addressed by post number rather than by page. Start at post 1 · go to the accepted answer.

j.nwosuTL2 Moderator15 May 2026#121

n.petrov, post #20: post #19 answers the question as asked. The question underneath it is different. Aspirating before injection: for subcutaneous injection, aspirating (pulling back on the plunger to check for blood) is not necessary and is sometimes discouraged because it is associated with more discomfort. Subcutaneous injection without aspiration is… Go to post

Sharps disposal: needles and syringes should be disposed in a sharps container (a rigid, puncture-resistant container). Do not put them in regular trash. Many pharmacies accept filled sharps containers.

11 likes in reply to #20 2mo

b.petrovTL2 Moderator15 May 2026#122

post #121 answers the question as asked. The question underneath it is different.

I disagree with the reply above, and I think the disagreement is substantive rather than terminological.

The distinction being drawn does not survive when you look at the published data for this specific question. I would be glad to be shown wrong on this, because the version I am arguing against is more convenient.

3 likes 2mo

e.piresTL2 Moderator15 May 2026#123

Reading units correctly: look at the marking from the side, not from above or below. The bottom of the plunger tip is the reading. Parallax error (wrong angle) is a source of dosing error.

0 likes 2mo

a.kowalskiTL2 Moderator16 May 2026#124

Fixed versus detachable needles: insulin syringes usually have fixed needles (no dead volume loss to the hub). Luer-lock syringes use detachable needles (more dead volume). Fixed needles are preferred for small doses.

32 likes 2mo

m.yilmazTL2 Moderator16 May 2026 · edited#125

Worth separating two things that post #121 runs together.

Needle gauge: smaller numbers (30G) are finer and less painful. Larger numbers (25G) are courser. For subcutaneous injection, 27-30G is typical. Finer needles take longer to draw up but hurt less.

16 likes 2mo

This topic was referenced in

A ten-fold dose error caught before injectionDevices › Syringes & needles · 103 replies
Reading U-100 graduations, with a conversion table — what changed sinceDevices › Syringes & needles · 2 replies

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