WHAT IS IN VAPE LIQUID? A COMPLETE GUIDE TO E-LIQUID INGREDIENTS (UK 2026)

Key Takeaways

• Most regulated UK vape liquids contain just four main ingredients: Propylene Glycol (PG), Vegetable Glycerine (VG), flavourings, and optional nicotine.

• Unlike cigarettes, vape liquid contains no tobacco and does not produce tar or carbon monoxide, making regulated vaping a lower-risk alternative(1) for adult smokers who switch completely.

• Choosing UK-regulated, high-quality vape liquids from trusted manufacturers helps ensure consistent ingredients, reliable performance, and compliance with UK safety standards.

Understanding What Is in Vape Liquid

If you've ever wondered what is in vape liquid, the short answer is that most e-liquid ingredients come down to four components: Propylene Glycol (PG), Vegetable Glycerine (VG), flavourings and optional nicotine. For adult smokers in the UK who are thinking about switching from tobacco cigarettes to vaping, or who already use an e-cigarette and want to know exactly what they are inhaling, understanding vape liquid ingredients helps you make more informed choices.

Vape liquid, also known as e-liquid or vape juice, is the liquid inside an electronic cigarette or vape refill that creates vapour when heated. Unlike tobacco cigarettes, vape liquid does not contain tobacco leaves and is not burned. Instead, an e-cigarette heats the liquid to create an aerosol that delivers flavour and, if chosen, nicotine.

In the UK, all nicotine-containing vape liquids must comply with strict regulations under the Tobacco and Related Products Regulations (TRPR)(2), helping ensure product quality and consumer safety. Below, we break down the main ingredients in vape liquid, how regulated UK vape liquids are assessed for safety and chemical content, what to look for when choosing a quality product, and how SMOKO’s UK-made vapes and e-liquids fit into that picture for smokers looking for a lower-risk alternative to cigarettes.

The Four Primary Ingredients in Vape Liquid

Propylene Glycol (PG)

Propylene Glycol (PG) is one of the main vape liquid ingredients found in many e-liquids.

PG is a clear, colourless liquid that has been widely used for many years in foods, medicines and cosmetics. In nicotine vape liquid, it carries flavour efficiently, and higher-PG blends give sharper flavour and a more distinct throat feel, but create less visible vapour; it also creates a thinner liquid that performs well in closed pod systems and helps deliver nicotine consistently.

50/50 e-liquids balance PG and VG for versatile vaping and are commonly used in MTL starter kits.

Because PG is less viscous than Vegetable Glycerine, it is commonly used in prefilled pod systems such as those available from SMOKO, helping provide reliable performance without leaking or clogging, and 50/50 liquids also work well in beginner-friendly vape pens.

Vegetable Glycerine (VG)

Vegetable Glycerine (VG) is the second major ingredient in vape juice.

Derived from vegetable oils, VG is thicker than PG and naturally has a slight sweetness. Its primary role is producing the visible vapour created when using an e-cigarette, and high VG e-liquids produce larger clouds of vapour. VG also contributes to a smoother inhale and a softer throat hit than higher PG formulations. A 70/30 VG/PG blend is popular for sub-ohm vaping because it suits thicker liquid made for cloud-focused use.

Manufacturers use different PG and VG ratios depending on the type of vaping device. Closed pod systems are generally designed with carefully balanced formulations that deliver consistent flavour, smooth vapour production and dependable performance, while high-VG formulations are better matched to more powerful devices, including sub ohm vape kits.

E-Liquid Flavourings

Flavourings give vape liquid its distinctive taste.

The flavour concentrates used in reputable UK vape liquids are typically food-grade ingredients specially formulated for e-liquids. Although flavourings represent only a small percentage of the finished product, they have a significant impact on the overall vaping experience.

Adult smokers can choose from a wide range of e-liquid flavours, from traditional tobacco and fruit to drink-inspired and dessert-style options. In particular, menthol flavours and ice blends provide a refreshing vaping experience. A popular vape juice flavours example is lemonade, which appeals to many adult vapers moving from disposables. Sweet flavours often include dessert profiles such as vanilla custard and caramel. SMOKO offers a broad selection, and each vape juice flavour is made using UK-made e-liquid for consistent quality and flavour.

Nicotine Salts vs Freebase Nicotine

Nicotine is an optional ingredient in vape liquid.

Many adult smokers choose nicotine vape liquid(3) because it provides nicotine without burning tobacco. In the UK, nicotine strength is legally limited to 20mg/ml (2%), and all nicotine-containing vaping products must comply with strict regulatory requirements before they can be sold. Nicotine is addictive and can increase heart rate and blood pressure.

SMOKO offers nicotine strengths designed to suit different adult smokers, allowing users to choose the option that best matches their previous smoking habits. The company also offers nicotine-free alternatives for adults who prefer vaping without nicotine.

Unlike some disposable vapes that use nic salt e liquid, often chosen because nic salts provide smoother throat hits at higher strengths and faster nicotine absorption than freebase nicotine, SMOKO's UK-made e-liquid contains freebase nicotine, which provides the familiar throat hit that many former smokers enjoy. For adult smokers, device choice and how much nicotine they use both affect overall nicotine intake.

What Is E-Liquid Made Of?

Many people ask what is vape juice made of, but the answer is relatively simple.

Most regulated UK e-liquids contain only Propylene Glycol (PG), Vegetable Glycerine (VG), flavourings and optional nicotine. Unlike cigarette smoke, vape liquid does not contain tar or produce carbon monoxide because there is no tobacco combustion.

Although vaping is not risk-free, UK health organisations continue to conclude that vaping can be an effective tool for adult smokers who switch completely from cigarettes.

Are There Chemicals in Vape Liquid?

Yes, but it is important to understand what that means.

Everything around us, including water, is made from chemicals. The ingredients used in regulated UK vape liquids are clearly identified and manufactured to strict quality standards. Unlike cigarette smoke, which contains thousands of chemicals produced by burning tobacco, vape liquid contains a relatively small number of ingredients before it is heated, and this does not typically include additives such as food colouring in regulated vape liquids.

Reputable manufacturers use high-quality ingredients and produce their e-liquids under carefully controlled manufacturing conditions. Most vape flavourings are suspended in PG to help them mix evenly throughout the liquid. SMOKO manufactures its e-liquid in the UK, helping maintain consistent quality and compliance with UK regulations.

How Is Vape Liquid Regulated in the UK?

The UK has some of the world's most comprehensive regulations for nicotine vaping products.

Before nicotine-containing vape liquids can be legally sold, manufacturers must submit detailed product information to the Medicines and Healthcare products Regulatory Agency (MHRA). UK regulations also limit nicotine strength to 20mg/ml, restrict pod and refill sizes to 2ml, require ingredient reporting and toxicological assessments, and mandate child-resistant, tamper-evident packaging with appropriate health warnings. Many of these rules sit within the wider EU framework of the Tobacco Products Directive. 

These measures help ensure that nicotine vaping products sold legally in the UK meet consistent standards for quality and consumer safety.

Does Heating Vape Liquid Create Harmful Chemicals?

When vape liquid is heated, small amounts of additional compounds can be produced.

However, scientific evidence consistently shows that regulated vaping products expose users to far fewer harmful chemicals than cigarette smoke. The greatest health benefit occurs when an adult smoker switches completely from smoking to vaping(4) rather than continuing to use both products.

Using genuine products designed specifically for your device and avoiding counterfeit or illicit vaping products can help minimise unnecessary risks.

How to Choose a Good Vape Liquid

When choosing an e-liquid or vape refill, it is important to pick one that suits your device, coil resistance and vaping style, while also complying with UK regulations, clearly identifying its ingredients, offering a suitable nicotine strength and being made by a reputable company. Different vape devices work best with different vape juices, such as pod-focused liquids for simpler setups and high-VG options for more powerful devices. Using genuine refills that are designed for your vaping device also helps ensure reliable performance and a consistent vaping experience.

SMOKO uses a closed, prefilled pod system in which every refill is manufactured specifically for its devices. This helps provide consistent flavour, dependable nicotine delivery and a straightforward vaping experience without the need to refill bottles manually. By contrast, a refillable vape kit or pod kits may suit users who want more control, and shortfill e-liquids can be mixed with nicotine shots to customise nicotine strength.

What Is in SMOKO Vape Liquid?

SMOKO's vape liquid contains the same four core ingredients found in most regulated UK e-liquids: Propylene Glycol (PG), Vegetable Glycerine (VG), food-grade flavourings and optional freebase nicotine.

SMOKO's e-liquid is manufactured in the UK and designed exclusively for its closed pod and Vape Max refill systems. This ensures each refill delivers consistent flavour, smooth performance and reliable nicotine delivery while meeting UK regulatory requirements.

Conclusion

Understanding what is in vape liquid is easier than many people expect. Most vape liquid ingredients consist of only four components: Propylene Glycol, Vegetable Glycerine, flavourings and optional nicotine.

Although vaping is not risk-free, regulated UK vape liquids are manufactured to strict standards and contain far fewer ingredients than cigarette smoke produced by burning tobacco. For adult smokers who switch completely, UK public health guidance states that vaping can be an effective aid to quitting cigarettes(5).

Choosing a trusted UK brand such as SMOKO, with UK-made e-liquid, genuine prefilled refills and products designed to comply with UK regulations, can help provide a simple, reliable and consistent vaping experience.

Frequently Asked Questions

What is in vape liquid?

Most regulated UK vape liquids contain four main ingredients: Propylene Glycol (PG), Vegetable Glycerine (VG), food-grade flavourings, and optional nicotine. These ingredients work together to create vapour and deliver flavour when heated.

Does vape liquid contain tobacco?

No. Vape liquid does not contain tobacco leaves and is not burned. Instead, an e-cigarette heats the liquid to produce an aerosol, avoiding the tar and carbon monoxide created by burning tobacco.

What is the difference between PG and VG?

Propylene Glycol (PG) carries flavour well and provides a stronger throat hit, while Vegetable Glycerine (VG) produces more vapour and creates a smoother inhale. The balance between PG and VG depends on the type of vaping device and the desired vaping experience.

Is nicotine included in all vape liquids?

No. Nicotine is optional. Vape liquids are available in a range of nicotine strengths, including nicotine-free options. In the UK, nicotine-containing e-liquids are legally limited to a maximum strength of 20mg/ml.

Are UK vape liquids regulated?

Yes. Nicotine-containing vape liquids sold legally in the UK must comply with strict regulations, including ingredient reporting, product testing, child-resistant packaging, and limits on nicotine strength, helping to ensure consistent quality and consumer safety.

References

(1) Vaping: What You Need to Know

(2) E-Cigarette Regulations for Consumer Products

(3) Use of Vapes Among Adults in Great Britain

(4) Tobacco: Preventing Uptake, Promoting Quitting and Treating Dependence (NG209)

(5) Using E-Cigarettes to Stop Smoking

ABOUT THE AUTHOR

Written by Mike Cameron

Mike Cameron is a former smoker of 15 years (2 packs a day) until he successfully quit using a cigalike.  Mike is the Co-Founder and CEO of SMOKO E-Cigarettes and over the last 13+ years, SMOKO has prevented 850M+ cigarettes from being smoked, helped their customers save £510M+ of their hard-earned money from going up in smoke and helped 10,000’s of adult smokers in 25+ countries to live smoke-free.

Last updated 04/08/2026