I've been tracking my 1 mL 31G insulin syringes for four weeks. Ten pulls from the same 3 mL vial, same technique, and when I weigh the syringe after emptying, I'm seeing 6-8 units left in the hub/needle. My cheap 0.01 g scale says 0.07-0.09 g.
Is that dead space, vial pressure, stopper coring, or me not bottoming the plunger hard enough? Has anyone measured this across different syringe brands with bac water?
Dead space is real. My fixed-needle 31G holds about 5 units.
Are you zeroing the scal ewith the plunger fully depressed? I got different numbers when I tared dry vs wet.
0.01 g is too coarse for 6 units. Mine jumps 0.01 at a time, so your 0.07 could be 0.065 to 0.075.
I ran a similar check with 10 U-100 syringes and a 0.001 g scale. Drew 100 units of bac water, expelled until the plunger stopped, weighed residual. Average was 0.053 g, about 5 units, but spread was 0.038 to 0.081 g. The high ones had visible bubbles in the hub.
Tapping and waiting 10 seconds before the final push made my repeats tighter. I also weighed empty syringes first to subtract residual water. Not saying it explains every unit, but bubbles deserve a look before you blame the barrel or stopper.
Fellow scale nerd here — your 0.01 g scale is the weak link before anything else. Mine reads 0.02-0.04 g of drift if I tare twice in a row, so a 0.07-0.09 g reading is basically two ticks of noise. Try weighing the same dry object ten times and look at the spread.
If that spread is wider than your result, you're measuring your scale, not your technique.
Honestly I stoped chasing the last unit and just track weekly averages now. Way less crazy-making for me.
Waist and belt notches told the truer story for me. I dropped two belt holes over six weeks while the scale bounced around the same four pounds, thanks to salt, hormones and one bad pizza Friday. Same with a pair of jeans I'd retired — fit fine by week seven. Numbers are noisy, fabric doesn't lie.
Measure your waist once a week, same spot, right when you wake up, and you'll see the trend the scale hides.
Counterpoint: I went down that rabbit hole for two months of weighing everything and it made me miserable without changing a single outcome. What actually moved the needle was boring stuff — same bedtime within 30 minutes, a 20-minute walk after dinner, and not letting Friday and Saturday turn into a two-day free-for-all.
My weekly average dropped about 1.2 lbs early, flattened to 0.4-0.6 around week ten, then popped again after a trip where I ate more than usual. Two weeks later I was down 3 lbs from before the trip.
The trend line is real, but it looks like a staircase, not a slope, and micromanaging a fraction of a gram is chasing noise inside noise.
0.01 g scale is way too coarse for single-unit stuff; mine drifts 0.03 g just from breathing on it.
I’m two years into the empty-nest reboot, and I did the same microscope thing for a bit. What finally helped was checking whether the leftover is in the hub or back in the barrel.
Mine was a tiny bead in the hub, and it changed when I switched syringe lots — same size/gauge, different plunger tip. I started writing the lot number on a sticky note on the vial so I wasn’t blaming my shaky hands every week.
Does yours look like a bead at the needle base or a streak up the side?
My spreadsheet calls it the syringe tax: tiny, consistent, and still annoying.
Tbh i quit weighing syringes and counted draws per vial instead. Over a few months, I consistently got one extra draw at the tail end, roughly matching the hub volume. So it wasn’t lost—just parked in the needle until the vial ran low.
The thing that changed my numbers most wasn’t dead space; it was pausing a second after the plunger hit bottom before pulling out. Do you notice the residual changes with a slower push, or is it dead constant?
I wnt down this hole too. What finally made it click: weigh the whole syringe before and after, not just after—my cheap scale only behaves if I do the exact same motion twice.
Also, my 4pm snack-drawer chaos was a bigger log-killer than any hub loss; if I’m grazing while unpacking backpacks, I swear the syringe ate extra. Are you weighing with the needle still on? Mine reads different if I pull it off first.
Known variable. I log the syringe tax and stop chasing it. 😅
One thing I added to my tracker: plunger position at full depress. Name-brand vs generic gave me a ~0.02 g difference on the same scale, same technique.
I also log lot number now, because one batch was consistently worse than the last. Curious if your 6–8 is steady per lot or jumps between boxes? That’s the only variable that ever moved my numbers.
Girl same, I stopped weighing after the hub became my tiny nemesis 😅
Yep, hub tax is real; I just log it and quit fighting the plastic 😅
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