If you vape, you’re probably familiar with the terms vegetable glycerin (VG) and propylene glycol (PG). PG and VG are the two main solvents used in e-liquids. And, when it comes to the PG vs VG debate, there are quite a lot of unsupported claims out there. Not only about their safety but about their qualities, and strengths/weaknesses as e-liquid ingredients.
We decided to look at the research behind the two ingredients and what we found, might surprise even the most seasoned vapers!
PG vs VG: The Basics
First, a quick introduction to PG and VG for anyone who is unfamiliar.
Propylene Glycol (“PG”) is a clear, synthetic, syrupy liquid that is often used as a food additive or component of cosmetic products. While recognized as safe by the FDA, it is important to note that PG is a synthetic ingredient. That means it’s a product of chemistry as a derivation of petroleum.
Vegetable Glycerin (“VG”) is a clear viscous liquid that is typically made from soybean, coconut, flaxseed, and palm oils. It has a wide range of uses in food, cosmetic, and pharmaceutical applications.
Contrary to PG, VG is a natural substance. While it is processed to create the final ingredient used in these products, it’s naturally sourced. A typical comparison of PG vs VG looks something like this:
The Importance of PG/VG for E-Liquid Flavor
The thing is, people’s vaping preferences vary over a wide range of different factors, from nicotine levels to cloud size. However, one thing all vapers can agree on is that flavor is important. When it comes to e-liquids, you’ll see all kinds of claims about how PG
“PG is a better flavor carrier than VG.”
This sentiment is very common in the vaping community, and sometimes seems to go unquestioned. But is it true?
Is PG really a “better flavor carrier” than VG?
The short answer is, NO. But, in order to really answer the question of PG and VG flavor carrying quality, we have to consider: (1) what this claim really means, and (2) how it could be demonstrated. Since we all use different mods and setups, consume different e-liquids with varying PG:VG ratios, and vape differently, questions about the actual differences between specific ingredients can be difficult to truly answer. With all the anecdotal claims out there regarding this question, we thought we’d see what science has to say about it.
Fortunately, the comparison of PG and VG as e-liquid ingredients has been researched from quite a few different angles in the scientific community. As the safety of vaping tends to take the spotlight of discussion, other interesting findings from the research about the vaping experience itself can easily be overlooked. One of these being the relationship between flavor and PG:VG ratios.
Fact: Users Cannot Distinguish Between PG/VG E-Liquids with Identical Flavoring
One 2018 study has some particularly interesting findings regarding qualitative differences between higher PG or VG content in e-liquids. This study investigates people’s ability to distinguish between higher PG or VG e-liquids with identical flavoring. The researchers used what is known as a “triangle test” to compare how people experience flavor with different e-liquid ingredients and PG:VG ratios. Triangle tests are a way to test for people’s ability to identify two different products. It works by presenting 3 blinded products, 2 of which are the same. Then the participant must identify which e-liquid is different.
Simply put, a test with this design allows researchers to see if one controlled variable is detectable. Here’s how it works:
Step 1: Select two products to be compared. In this case, VG and PG.
Step 2: Make a set of three products. A set with either consist of (2) VG and (1) PG, or (1) VG and (2) PG.
Step 3: Present this set of three products to participants. Then ask them to identify the product with only one appearance in the set.
Step 4: Record responses and perform statistical analysis to determine results.
In the 2018 study, researchers used varying PG:VG ratios for these tests, including both PG and VG dominant e-liquids. Their findings contain the following conclusions:
“Established vapers in this study were unable to distinguish PG:VG ratios consistently, even for relatively large differences, and correct identification inconsistently related to subjective effects ratings. These preliminary findings suggest that the PG:VG ratio may not be a salient feature of vaping” (Schnellar et al., 2018).
When PG and VG ratios are controlled for, it turns out that people can’t really tell the difference between PG and VG dominant e-liquids. These findings suggest that the popular idea that “PG carries flavor better than VG” is demonstrably false. If it were true, people would be able to tell the difference between the products based on flavor intensity. The researchers also go on to explain that since people were unable to identify the odd product in the triangle tests, the nicotine content and flavor choices are more likely the key features of the vaping experience.
Why Are We Told PG Carries Flavor?
First off, PG provides a cost savings and therefore offers a higher profit margin for manufacturers.
Another common component in PG e-liquids are artificial sweeteners. These sweeteners provide a more pronounced flavor profile. Unfortunately, they come with their own sets of problems, such as gunking up coils.
Even as industry professionals, many manufacturers have been told PG is a necessary flavor carrier. And it’s been happening for so long that we have come to accept it without challenge. This trend has been changing recently as more awareness over the dangers of PG have come to light.
You may be thinking, “I have tried PG and VG e-liquids and I CAN TELL THE DIFFERENCE”.
The difference that you may be experiencing isn’t necessarily due to PG vs VG in your e-liquids but can be attributed to artificial flavors, synthetic sweeteners, and additives. Without having sampled a PG free e-liquid without these ingredients, you might not have had the opportunity to experience what a Max-VG e-liquid with organic, all-natural ingredients can offer in terms of flavor!
The Differences Between PG and VG
Now, just because users cannot distinguish flavor differences between the two is not to say that PG and VG are substitutes for one another. They are different substances with different physical and chemical properties, and they do have demonstrable differences in characteristics when vaped, such as cloud density, nicotine delivery, and harshness to the airways.
Another study from 2018 looked at various dimensions of vaping PG vs VG e-liquids, including puff topography, nicotine delivery, harshness, and overall user satisfaction.
Throat Hit & Nicotine Delivery
This study found that products made with PG were “significantly less favorable relative to all other e-liquids,” due largely to the fact that harshness increased with higher PG ratios (Spindle et al., 2018). The same study also found that PG e-liquids were “less satisfying overall to participants than the two VG-based e-liquids.” In other words, e-liquids made with PG are harsher and less satisfying when people aren’t aware of which e-liquids they are vaping. In almost every case, the more intense “throat hit” that is associated with PG e-liquids prevented users from being able to draw as deep of a hit when vaping PG e-liquids, and in turn, found the vapor to be less satisfying.
PG Allergies vs. VG Allergies
It’s also worth noting that PG allergies and sensitivity are far more common than VG allergies. In fact, about 0.8% to 3.5% of the population is susceptible to PG allergies, while only 4 cases of VG allergy have ever been documented (Jacob et al., 2018, Suzuki et al., 2018). While the exact reason for this is unknown, it has been hypothesized that the human body is simply more forgiving when it comes to natural ingredients like vegetable glycerin than it is to synthetic chemicals like propylene glycol.
All of this data strongly suggests that the perceptibility of PG vs VG is negligible in seasoned vapers, and that PG doesn’t actually play a significant role in carrying flavor. PG does however carry increased risks that simply aren’t necessary for an enjoyable vaping experience, and tends to actually be less satisfying than VG liquids. With conclusive data indicating that VG flavors can be just as powerful, and even more enjoyable, we expect to continue seeing more & more vapers switch to a cleaner alternative.
Vegetable Glycerin: A Cleaner Alternative
In light of studies like these, we can make much more informed decisions when looking at the variety of vape juices on the market today. As we covered above, PG isn’t the necessary flavor carrier it’s been touted to be.
In contrast, it’s actually a chemical additive that has been proven to be unnecessary to produce exceptional flavor in e-liquids. All of our USDA Certified Organic e-liquids here at Essence Vapor are 100% VG. And, they are free from PG, artificial flavors, sugars, GMOs, and additives. Do a side to side test yourself and see how incredible the flavor from organic, all-natural ingredients can be!