CBD e-liquid: understanding the mg/ml dosage and the composition

The concentration is obtained by dividing the total quantity by the volume. A 10 ml bottle at 300 mg therefore contains 30 mg per millilitre. The same 10 ml bottle advertised at 1000 mg contains 100 mg per millilitre, and a 30 ml bottle advertised at 300 mg contains only 10.

This is the most frequent source of error: the number highlighted on the label is almost always the bottle's total, never the concentration. Comparing two products without bringing their values back to the millilitre amounts to comparing different quantities.

On what an inhaled quantity represents, caution is required. A systematic review published in 2018 in Frontiers in Pharmacology, covering the pharmacokinetics of cannabidiol in humans, retains an absolute bioavailability of 31% by inhalation. Its authors point out, however, that no study has established an absolute bioavailability for the oral route in humans. The numerical comparisons between inhalation and ingestion commonly read online therefore do not rest on human data, and we will not repeat them.

An e-liquid rests on two carriers, propylene glycol and vegetable glycerine, whose proportions determine the viscosity and the behaviour when heated. No vegetable oil enters into this composition, and that is the central safety point of this subject.

The reference episode is the outbreak of vaping-associated lung injury that occurred in the United States. The final tally published by the Centers for Disease Control and Prevention reports 2,807 hospitalisations or deaths as of 18 February 2020, including 68 deaths, with vitamin E acetate strongly associated with the outbreak and found in the bronchoalveolar lavage fluid of 48 patients out of 51.

A point of honesty is required here, because the claim often circulates in a false form. The analysis report published in 2019 by the same authorities indicates that, across 29 bronchoalveolar lavage samples, vitamin E acetate was detected in all 29, while vegetable oils, fractionated coconut oil and petroleum distillates all sat below the detection limits. It would therefore be inaccurate to write that fractionated coconut oil caused these injuries. The agent implicated is vitamin E acetate, and the general principle that follows from it remains valid: a fatty substance has no place in an inhaled aerosol.

A second technical point, often ignored. A study published in 2021 in Scientific Reports shows that propylene glycol and glycerol degrade at temperatures between 133 and 175°C under oxidising conditions, producing formaldehyde, acetaldehyde and propionaldehyde. Degradation therefore begins well before a burnt taste appears. Powering a coil beyond its range, or drawing on a dry wick, is not harmless. Our article on vaporisation temperatures covers the same principle for flower.

Vaping remains a legal format in France. The withdrawal of ingestible CBD products, recalled by the Ministry of Agriculture in May 2026, targets foodstuffs: an e-liquid does not fall into that category. Let us note, however, that its legality flows from its absence from the food domain, not from a positive authorisation of its own.

The law of 24 February 2025 banned single-use electronic vaping devices, that is, pre-filled and non-refillable ones. Cartridges are expressly excluded from that ban, and refillable devices, like bottles of e-liquid, are not concerned. We detail this measure in our article on the ban on disposable puffs.

The Δ⁹-THC content threshold remains that of ordinary hemp law: paragraph III of article 1 of the decree of 30 December 2021 sets at 0.30% the maximum content of extracts and of the products that incorporate them, e-liquids included.

This is the subject on which the French authorities have been most explicit. In a statement of 19 June 2025, the ANSM reports several hundred poisonings since the start of 2024 among consumers of products presented as containing CBD, with e-liquids explicitly among the formats concerned.

The substances involved are synthetic or semi-synthetic cannabinoids, notably HHC, HHC-O, H4-CBD and MDMB-PINACA, or THC above the legal threshold. The same statement recalls that a 2023 study found a CBD content different from that indicated on the labelling for 8 products out of 10, and lists symptoms ranging from tachycardia to hallucinations and loss of consciousness.

The practical conclusion is simple: on this format, the statement carried on the bottle is not proof. Only a per-batch certificate of analysis, mentioning the cannabinoid profile and the absence of synthetic cannabinoids, answers the question. Our article on reading a certificate of analysis details the lines to check, and our comparison of e-liquids covers the choice of formats.

A 10 ml bottle at 300 mg — how much is that per millilitre?

Thirty milligrams per millilitre. The quantity advertised on the label corresponds to the total contained in the bottle, and the concentration is obtained by dividing it by the volume. A 30 ml bottle advertised at 300 mg therefore contains only 10 mg per millilitre, for an identical total quantity.

Can you vape a CBD oil?

No. An oil is intended for another use and does not enter into the composition of an e-liquid, which rests on propylene glycol and vegetable glycerine. The American outbreak of vaping-associated lung injury, which totalled 2,807 hospitalisations or deaths, was strongly associated with vitamin E acetate, a fatty substance added to vaping products.

Are CBD e-liquids still authorised in France?

Yes. The May 2026 withdrawal covers foodstuffs containing CBD, a category e-liquids do not fall into. The law of 24 February 2025 also bans single-use, pre-filled and non-refillable devices, without targeting bottles or refillable devices.