I've always been under the impression that 1 tab is a serving. I think this part of the description answers your question. Just pay attention to the first sentence.
DESCRIPTION:
Each tablet is cross scored, allowing you to take 1/2 or even 1/4 doses. This comes in handy if you have a low tolerance to stimulants or if you would like to take smaller more frequent doses. Each tablet, made from the finest pharmaceutical grade chemicals available.
Contains: 25mg of norephedrine, 100mg of caffeine and 2.7mg of yohimbine hcl.
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