Benefits
Improved Chromium Absorption
In one small study of six adults, more chromium turned up in the urine after a single 200 mcg dose of chromium histidinate than after the same dose of chromium picolinate or the other forms tested, which the researchers read as better absorption. That is the only human finding for this ingredient. Absorption is not the same as benefit, and no health outcome was measured.
Chromium's Role in Glucose Metabolism
Chromium is involved in how the body handles carbohydrate and responds to insulin, and this form is sold as a way to deliver it. No human trial has tested chromium histidinate for blood sugar, insulin or body weight, so nothing in this pathway has been shown to change in people who take it.
Amino-Acid-Chelated Form
Binding chromium to histidine is meant to help the body take up a mineral that is otherwise absorbed poorly. That is the entire rationale for the form, and the only support for it is the six-person absorption study described above.
Preclinical Metabolic Interest
The metabolic claims made for this form come from a single 2011 study in rats fed a high-fat diet, which reported changes in blood sugar, insulin and liver markers. Rats are not people, and none of it has been tested in a human trial.
Mechanism of action
Histidine-Enhanced Absorption
Histidine chelation is thought to keep chromium soluble and improve its uptake across the intestinal wall, which is the mechanism behind the better absorption seen for chromium histidinate versus picolinate in the human study.
Proposed Insulin Signaling Support
Trivalent chromium is hypothesized to enhance insulin receptor signaling and glucose uptake. For chromium histidinate the only supporting experiments are in rodents. There is no human efficacy evidence for this form at all.
Preclinical Metabolic Effects
In rats fed a high-fat diet, chromium histidinate was reported to change blood sugar and insulin levels, chromium content in the liver, and markers of glucose transport and of antioxidant and inflammatory signalling. These are laboratory measurements in animals and say nothing about what happens in a person.
Not an Established Essential Nutrient
Whether chromium is truly an essential nutrient is still debated among nutrition scientists, and there is no clearly defined deficiency disease in people. Neither of the two studies cited on this page addresses that question, so treat it as background rather than a finding about this form.
Clinical trials
Human study assessing stability and absorption of chromium complexes, comparing chromium histidinate with chromium picolinate and other forms by measuring urinary chromium excretion after a 200 mcg oral dose.
Six healthy adults (three men, three women).
Chromium histidinate was absorbed better than chromium picolinate and the other chromium forms tested, based on greater urinary chromium excretion. With six people, a single dose and no health outcome measured, this is a very small study of absorption only. Blood sugar, insulin, weight and every other outcome were left untested.
Animal study of chromium histidinate in rats fed a high-fat diet, measuring blood sugar and insulin in the blood, chromium levels in the liver, and molecular markers of glucose transport and of antioxidant and inflammatory signalling.
Rats with diet-induced obesity; preclinical, not human.
The rats given chromium histidinate showed changes in blood sugar, insulin and the liver markers that were measured. This is the only study behind every metabolic claim made for this form, and it was done in rodents, so it does not show that the supplement does anything for blood sugar, insulin or weight in a person.