Never tested together

The combinations nobody has studied.

1,481 pairs of supplements people take together, and for each one we ran the search and found no trial that gave both. The gap is the point. Here are the 40 most searched.

The ones people ask about most

Magnesium + L-theanineSearched about 5,400 times a month. No trial has tested the pair.

Ashwagandha + L-theanineSearched about 2,900 times a month. No trial has tested the pair.

Magnesium + ashwagandhaSearched about 2,400 times a month. No trial has tested the pair.

Vitamin D + vitamin B12Searched about 2,400 times a month. No trial has tested the pair.

Collagen + biotinSearched about 1,600 times a month. No trial has tested the pair.

Vitamin D + vitamin CSearched about 1,600 times a month. No trial has tested the pair.

The next 34, and how often each is looked up

Ashwagandha + melatonin1,000 a month
Ashwagandha + Rhodiola rosea880 a month
CoQ10 + PQQ880 a month
Echinacea + elderberry880 a month
Elderberry + zinc880 a month
GABA + L-theanine880 a month
Berberine + chromium720 a month
Magnesium + turmeric590 a month
Melatonin + L-theanine590 a month
Valerian root + melatonin480 a month
Turmeric + berberine390 a month
Ashwagandha + turmeric320 a month
Maca root + ashwagandha320 a month
Boron + zinc260 a month
L-carnitine + taurine260 a month
Turmeric + vitamin C260 a month
Ashwagandha + lion’s mane210 a month
Berberine + L-carnitine210 a month
Biotin + folate210 a month
Creatine monohydrate + vitamin D210 a month
Vitamin B12 + potassium210 a month
Vitamin D + CoQ10210 a month
Vitamin D + melatonin210 a month
Ashwagandha + berberine170 a month
Iron + biotin170 a month
L-tyrosine + 5-HTP170 a month
Turmeric + potassium170 a month
Ashwagandha + zinc140 a month
Kava + valerian root140 a month
L-tryptophan + L-theanine140 a month
Vitamin B12 + probiotics140 a month
Ashwagandha + vitamin D110 a month
Boron + vitamin D110 a month
5-HTP + melatonin90 a month

Why this page exists

A supplement label can say a combination is synergistic without anyone ever having given the two together in a trial. That gap is invisible when you shop, so we drew it. An empty space between two capsules is not us being unsure. It is the finding.

We never call a pair untested on a hunch. Each one here comes from a search we ran against PubMed and kept, with its query, its date and its hit count, and every pair page shows you that search. We have screened 4,685 pairs. 4,226 came back with no trial of the pair at all, and 1,481 of those join two supplements that both have a scored page, which is what lets us draw them. A further 301 are still queued: their first search returned more hits than we read, and we do not call a pair untested on a sample.

The 40 above are the most searched of the 1,481. The rest arrive as more supplements get scored. The opposite page is does not work, where the trials do exist and the answer is no.