The DIY E-Liquid Underground: When Regulators Push, Consumers Become Chemists

The ingredients are available online: a liter of pharmaceutical-grade propylene glycol ($15), a liter of vegetable glycerin ($12), a bottle of 100mg/mL nicotine solution in propylene glycol ($40), and a selection of concentrated flavor compounds from any of a dozen suppliers ($3-8 each). With a digital scale ($25), some empty bottles ($10 for a pack), and a basic understanding of mixing ratios, anyone can manufacture e-liquid at home—for a fraction of the retail price, with complete control over nicotine strength, VG/PG ratio, and flavor profile. The DIY e-liquid community has existed since the earliest days of vaping, but it has grown significantly as flavor bans and product restrictions have restricted the availability of commercial e-liquids. When the legal market fails to provide the products that consumers want, consumers become producers. The DIY e-liquid underground is a case study in the limits of supply-side regulation.

The scale of the DIY e-liquid phenomenon is difficult to quantify precisely, but it is substantial. Online forums dedicated to DIY e-liquid mixing—r/ejuice on Reddit, E-Liquid-Recipes.com, Vaping Underground's DIY section—have hundreds of thousands of members. The supply chain for DIY ingredients has matured: nicotine solution is available from a handful of specialized suppliers who provide certificates of analysis and child-resistant packaging; flavor concentrates are sold by companies that primarily serve the food and beverage industry but have developed product lines and safety guidance for vaping applications; and the equipment and consumables (scales, bottles, pipettes, labels) are commodity items available from general laboratory-supply retailers. The infrastructure for DIY e-liquid production is accessible, affordable, and—for the most part—technically legal (nicotine solution over a certain concentration is restricted in some jurisdictions, but enforcement is minimal). The DIY community is not hidden. It operates in plain sight, on platforms that regulators can access but have not effectively addressed.

The safety concerns associated with DIY e-liquid production are real and should not be minimized. Concentrated nicotine solution (100mg/mL or higher) is toxic—dermal exposure can cause nicotine poisoning, and ingestion of even small quantities can be fatal. The DIY community has developed safety protocols (gloves, eye protection, dedicated mixing area, proper storage of nicotine solution) that are consistently emphasized in community resources, but compliance is voluntary and varies by individual. The flavor concentrates used in DIY mixing are the same concentrates used in the commercial e-liquid industry—and, as discussed elsewhere, their inhalation safety is largely unknown. The mixing environment—typically a home kitchen or workspace—lacks the quality control, contamination prevention, and batch-testing infrastructure of commercial manufacturing facilities. The regulatory framework that governs commercial e-liquid manufacturing—GMP (Good Manufacturing Practice) requirements, batch testing, ingredient traceability—does not apply to the individual mixing e-liquid at home. The DIY community, for all its emphasis on safety and technical precision, operates in a regulatory void.

The emergence of the DIY e-liquid underground is a predictable consequence of flavor bans and product restrictions. When a consumer cannot purchase their preferred flavored e-liquid from a legal commercial source, they have several options: switch to an unflavored or tobacco-flavored product (which many find unsatisfying), purchase flavored products from illicit sources (black market, cross-border online retailers operating outside the regulatory perimeter), or manufacture the product themselves from legally available ingredients. The DIY option is, in many ways, the safest of the three: the ingredients are purchased from regulated suppliers, the production process is under the consumer's control, and the consumer is not exposed to the risks of the illicit market (contaminated products, unknown ingredients, no recourse for quality issues). But the DIY option also represents a regulatory failure: the flavor ban, intended to protect consumers from unsafe products, has pushed consumers into an unregulated production environment with its own safety risks. The regulation that was supposed to make vaping safer has, for a segment of consumers, made it less safe.

The regulatory response to the DIY phenomenon has been inconsistent and largely ineffectual. Some jurisdictions have attempted to restrict the sale of concentrated nicotine solution—the EU's Tobacco Products Directive limits nicotine concentration in retail e-liquid to 20mg/mL, which makes DIY mixing more difficult (the mixer must use larger volumes of dilute nicotine solution) but not impossible. Other jurisdictions have not addressed DIY production at all, focusing enforcement resources on commercial manufacturers and leaving the home-mixing community in a de facto legal gray zone. The fundamental challenge is that the ingredients for DIY e-liquid—propylene glycol, vegetable glycerin, flavor concentrates, and nicotine solution at moderate concentrations—have legitimate uses beyond vaping (food, pharmaceutical, and cosmetic applications), making them difficult to restrict without collateral effects on other industries. The DIY e-liquid community exists because the ingredients for e-liquid are simple, widely available, and difficult to regulate without regulating a much broader set of chemical products.

The DIY e-liquid phenomenon illustrates a broader principle of nicotine regulation: when the legal market fails to provide the products that consumers demand, consumers will find ways to meet their own demand. The alternatives—DIY production, cross-border online purchasing, illicit local markets—are all less regulated than the commercial market that regulation has suppressed. The policy choice is not between a regulated market and no market. It's between a regulated market and an unregulated market—and the unregulated market, by its nature, is less safe. The DIY e-liquid community is not, on balance, a public health disaster—the health risks of DIY production are modest compared to the health risks of the smoking that DIY e-liquid users have presumably avoided. But the DIY community is a cautionary tale about the limits of supply-side regulation. When regulation pushes consumers out of the legal market, it doesn't push them into abstinence. It pushes them into the unregulated spaces where safety standards, quality control, and regulatory accountability do not apply.

Shareable insight: Flavor bans don't eliminate the demand for flavored e-liquids. They push production underground—into home kitchens and workspaces where consumers, acting as amateur chemists, mix their own. The DIY e-liquid community is a predictable response to supply-side regulation that restricts the legal market without providing satisfying legal alternatives. The ingredients are legal, the practice is largely unregulated, and the safety concerns—concentrated nicotine handling, unknown inhalation toxicology of flavor compounds—are the same concerns that the flavor bans were supposed to address.