What is vape juice made of?

Vape juice, or e-liquid, is typically made of a base of two carrier liquids, optional nicotine, and a complex mix of flavorings and other additives. While the core components are fairly standard, the specific flavor chemicals and any extra additives vary widely between products.

🧪 The Base: Propylene Glycol (PG) & Vegetable Glycerin (VG)

These two liquids make up the vast majority of any vape juice-often over 95% of the total volume.

Propylene Glycol (PG): A thin, colorless liquid. It carries flavor well and produces a stronger "throat hit" (the tingle you feel when inhaling). It's also known to cause dryness in the mouth and throat.

Vegetable Glycerin (VG): A thick, slightly sweet liquid. It is responsible for the large, visible vapor clouds. VG is smoother on the throat but needs to be thinned (often with PG or water) to work well in a vape device.

The ratio of PG to VG is a major factor in the vaping experience. A common ratio is around 60:40 PG:VG, but products can range from 100% PG to 100% VG depending on the desired throat hit and vapor production.

⚗️ Nicotine

Nicotine is an optional but common ingredient, available in various concentrations. It can come in different forms:

Free-base Nicotine: The traditional form, which provides a stronger throat hit.

Nicotine Salts: A smoother form that allows for higher nicotine concentrations without being overly harsh.

🍓 Flavorings & Coolants

This is the most variable part of the formula, making up the remaining ~5% or less. While these flavor chemicals are often approved for use in food, they are not approved for inhalation, and their safety when heated and inhaled is not established.

Common flavor chemicals detected in e-liquids include:

Vanillin & Ethyl Maltol: For vanilla and sweet, caramelly notes.

Benzaldehyde: Provides a cherry or almond flavor.

Menthol & WS-23: For cooling or "ice" effects. WS-23 is a coolant often detected in almost all disposable vapes tested in one study.

Diacetin: A common flavor solvent.

🔬 Other Additives & Potential Contaminants

Beyond the core ingredients, manufacturers may add other substances, and the heating process itself can create new compounds.

Additives: These can include water (to thin VG), organic acids (like benzoic acid to create nicotine salts), and antioxidants. Some products may also contain ingredients like CBD, THC, or other botanicals.

Thermal Degradation By-products: When PG and VG are heated, they can break down into other chemicals. These include formaldehyde, acetaldehyde, and acrolein, which are known irritants and potential carcinogens.

Heavy Metals: Trace amounts of metals like nickel, lead, and chromium can be present, potentially from the heating coil or other device components.

It's important to note that labeling can sometimes be inaccurate; one study found nicotine concentrations differed by up to 9% from what was declared on the label.