What do the states mean?+
- Solid: well studied, and it works.
- Half-there: the science is still forming.
- A ghost: almost no real studies.
- Hollow: well studied, and it does not work.
- A cord: the pair itself has been tested together.
- Air: nobody has ever tested this pair.
The full scoring method: How we score
Can you take glycine and valerian root together?
Nobody has tested this pair.
As of August 2026, no human trial has given glycine and valerian root together. We searched PubMed for trials naming both on 26 August 2026 and read every candidate it returned; none tested the pair.
4 studies · none tested the actual pair · 1 caution
See what each one is on its own
What you’re seeing
- Glycine renders half-there: for sleep, the science is still forming.
- Valerian root renders half-there: for sleep, the science is still forming.
- Nothing is drawn between them, because nothing has been run. The empty space is the review.
You can tell before you read a word.
Vitamin D + vitamin K2 is what the other answer looks like. Someone ran the study, so a cord is drawn between them. That is the whole difference.
Fair questions
Is it safe to take glycine and valerian root together?+
No trial has tested the combination, so there is no evidence either way. Nobody has found a problem, and nobody has looked.
Why does this page say nobody has tested it?+
Because we ran the search and read the results. The date above is the day we ran it. We do not claim a pair is untested without a logged search behind it.
Will this page change?+
Yes, if a trial publishes. We re-run these searches and the page changes from air to a cord the day the evidence does.
Deeper
The search we ran+
On 26 August 2026 we asked PubMed for trials, reviews and meta-analyses naming both glycine and valerian root. It returned nothing. We read every one and none gave the two together. This page carries a date because the answer can change: if a trial publishes, the air becomes a cord.
What each one is on its own+
Glycine
- Sleephalf-there
- Blood pressurehalf-there
Valerian root
- Sleephalf-there
Pairs that have been tested+
- Glycine has been tested with L-tryptophan, NAC.
- Valerian root has been tested with lemon balm.
These are the combinations someone has actually run a study on. Every other pairing here is air.
Worth knowing+
- Glycine is widely sold as a sleep aid. The human trials behind that come from one research group at Ajinomoto, an amino acid manufacturer, and are described in the company’s own review rather than pooled by independent analysts. We found no independent meta-analysis of glycine for sleep, so there is nothing here we can score.