Studies have demonstrated that CBD has a low affinity for the CB1 receptors, but even at low concentrations, CBD decreases G-protein activity (3). CB1 receptors are expressed on many glutamatergic synapses that have been implicated in seizure threshold modulation. CBD may act at CB1 receptors to inhibit glutamate release (4). Studies have shown changes in the expression of CB1 receptors during epileptogenesis and after recurrent seizures (5). CB1 receptor expression is upregulated at GABAergic synapses and shown to be downregulated at glutamatergic synapses in epilepsy, contributing to lowering seizure thresholds.

The immediate and powerful effects of THC are explained because of the special affinity it has with the CB1 type receptors, which mediate crucial processes in the brain. The less prominent (but no less important) action of CBD was explained, at least for a while, by hypothesizing that it binds to CB2 type receptors, hence its more diffuse manner of exercising changes in the body. Early on, the antipsychotic effects of cannabidiol were observed, an aspect which seemed to be in consonance with this initial hypothesis.
Transparency: cbdMD seems to be going through a transition with their third-party testing practices. Until recently, they only released a lab report for the CBD concentrate they use for all their products, but would not show potency testing for individual products. That seems to be changing. Currently, the only lab report on the website is for their concentrate (and it’s over a year old). But if you contact customer service, they’ll send you a lab report for any product. 
Tinctures – Typically tinctures are small glass or plastic “dropper” bottles that have cannabidiol oil mixed with a preserving solution such as alcohol. Tinctures were very a very common way to ingest botanical oils prior to the industrial revolution and are experiencing a resurgence in popularity as more people are looking for natural remedies. Tinctures with droppers allow you to put a few drops in your tea, under your tongue, or to bake the oil directly into your food.