Comment · Thu, December 25, 2025 · ND Owner
ND products testing positive for heavy metals
Original post in this thread
birdnerdcatlady · 0 points
I just got a shipment of L Carnosine and Mg glycinate today. I tested them both for heavy metals. Both are positive for lead and the Mg glycinate also tested positive for cadmium. I used 2 different test strips, both tested for lead only (both tests positive for each supplement) and one tested for multiple heavy metals. Has anybody else tested their supplments? For comparison my ND L Theanine tested negative for all metals .
What they were answering
whereismyface_ig · 3 points
** Short answer: the chemistry explanation given by the ND owner is basically correct, and the original Reddit post is not reliable evidence of heavy-metal contamination. The situation is more about misuse of test strips + misunderstanding analytical chemistry than about unsafe supplements.
Here’s a clear, grounded breakdown so you can judge it calmly 👇
⸻
1. The core issue: test strips ≠ supplement testing
Those consumer heavy-metal test strips are designed (poorly) for:
• screening water under limited conditions
• high contamination scenarios (paint chips, old toys, soil slurries)
They are not designed for:
• concentrated mineral supplements
• chelating compounds
• complex organic matrices
This isn’t ND marketing spin — it’s well-established analytical chemistry.
⸻
2. Why magnesium glycinate triggered a “lead positive”
This part is textbook.
What the strips use
Most of these strips rely on dyes like:
• Dithizone
• Rhodizonate
These dyes:
• bind to many metal cations, not just lead
• change color based on any strong metal interaction
What went wrong
Magnesium glycinate, once dissolved, produces:
• massive Mg²⁺ concentrations (thousands of times higher than trace metals)
So the strip:
• isn’t detecting lead
• is reacting to the magnesium itself
As the ND owner bluntly said (but accurately):
“You detected the magnesium you paid for.”
This is called…
u/MisterYouAreSoDumb · ND Owner
I hope that's what my gravestone reads.
Defensive? Yes. Abrasive? Yes. Unprofessional in places? Yes.
Ultimately correct? Yes.