It seems evident to me that e-juice can easily and legally be marketed as an herbal supplement, and thus NOT regulated by the FDA.
A claim like "nicotine has been shown to increase alertness" would qualify it as a supplement.
The only question is the "excluding tobacco" phrase in the following list. Because it is a tobacco extract and not tobacco itself... I think... means supplement?
Definition of Herbal Supplement:
In the United States, a dietary supplement is defined under the Dietary Supplement Health and Education Act of 1994[2] (DSHEA) as a product that is intended to supplement the diet and contains any of the following dietary ingredients:
a vitamin
a mineral
an herb or other botanical (excluding tobacco)
an amino acid
a dietary substance for use by people to supplement the diet by increasing the total dietary intake
a concentrate, metabolite, constituent, extract, or combination of any of the above
Furthermore, it must also conform to the following criteria:
intended for ingestion in pill, capsule, tablet, powder or liquid form not represented for use as a conventional food or as the sole item of a meal or diet labeled as a "dietary supplement"
Pursuant to the DSHEA, the Food and Drug Administration (FDA) regulates dietary supplements as foods, and not as drugs. While pharmaceutical companies are required to obtain FDA approval proving the safety or effectiveness of their products prior to their entry into the market, dietary supplements, like food, do not need to be pre-approved by FDA before they can enter the market.[5]
The claims that a dietary supplement makes are essential to its classification. If a dietary supplement claims to cure, mitigate, or treat a disease, it would be considered to be an unauthorized new drug and in violation of the applicable regulations and statutes