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Review: The New G Pen Pro Portable Vaporizer from Grenco Science


  • Manufactured By: Grenco Science
  • Manufactured In: China
  • Designed In: California
  • Designed For:
    • Dry Herb
See all specifications

Grenco Science, the company behind the original G Pen vaporizer, has quickly established itself as one of the largest and most well-recognized portable vaporizer manufacturers in the world. With celebrity endorsements from Snoop Dogg, Taylor Gang, DGK, and more, Grenco continues to look for ways to expand its reach and connect with the community; so far, the company has found a bundle of success.

The G Pen Pro is the company’s newest product offering and is the next generation of the original G Pro Herbal, a less-sophisticated vaporizer pen launched by Grenco in early 2014. Like the G Pro Herbal, the new G Pen Pro is designed specifically to vape dried herbs (not concentrates or liquids) and retails for the relatively low price of $99.95 USD.

Before we dive into the full review, I think it is important to note that the G Pen Pro is a “session” vape that stays heated for the entire life of the session, as opposed to a single-hitter that requires you to press and hold a button each time you want to take a draw. Naturally, this makes the G Pen Pro a decent option for those who like to take a lot of draws per vape session, and a less attractive option for those who prefer just 1-2 hits at a time. If you prefer the latter, you may want to consider browsing Medical Jane for other quality [single-draw] vaporizers.

Review: The New G Pen Pro Portable Vaporizer from Grenco Science

New Stylish Looks, Same Old Materials & Internal Workings

As is typical for Grenco, the company has taken steps to ensure that the newest addition to their product line is aesthetically pleasing. If you are looking for a pen that has a nice feel in your hand, and is small and light enough that you can carry it around discretely in your hand or slip it into your pocket for a few hours without much thought, then you are going to love the new G Pen Pro. It certainly looks chic and stealthy – some may even go as far as calling this vaporizer sexy.

But if you are looking for new features or advances in technology, the G Pen Pro isn’t going to excite you. I was happy to see a shortened heating time with the new pen; however, other than that and making the device a bit smaller, lighter, and better looking than its predecessor, it certainly feels like Grenco made little to no noticeable improvements to the device’s inner workings.

Not only that, but the company continues to use questionable/cheap materials despite health and safety concerns raised by us and other reviewers. This is a little disappointing because we look to leaders like Grenco to set the standard by making a commitment to enhancing the overall safety and functionality of vaporizers.

For example, the mouthpiece of the G Pen Pro is still made of plastic (PBT) with a melting point 240ºC [464ºF], rather than glass (preferred). Because of this, the vapor quality suffers, especially after long medicating sessions with continued use / increased internal temperatures. I know what you may be thinking…”but wouldn’t glass be more prone to breakage?” Yes, but glass is also cheap and easy to replace, inert, fairly heat-resistant, and typically improves overall vapor quality. To minimize breakage and allow for easy carrying, perhaps Grenco could implement some sort of push mechanism to either hide or extend the glass mouthpiece, similar to how a ballpoint pen works.

Perhaps we’ll see some exciting changes in the next generation, but only time will tell.

The material of the heating chamber is stainless steel. The white material around the heater is silicon, which has a melting point of 250ºC [482ºF] after a period of 30+ minutes of continuous heating.

Additionally, the small metal filter inside of the mouthpiece cover has tiny airways which tend to clog after just 2-3 sessions. Your purchase of the G Pen Pro does include a cleaning kit, with a brush that makes it relatively easy to keep clean with regular upkeep.

The G Pen Pro is a less than ideal option for getting the most flavor out of each draw – even when using top shelf herbs with strong terpene profiles. There is a burnt popcorn flavor that lingers after each draw, especially at higher temperatures, which only gets worse without the continued re-stirring of the ground material inside the heating chamber. This makes one wonder if it is due to poor design of internal mechanisms, the materials used (mentioned above), and/or because the unit uses conduction heating, which means that the ground material in the chamber risks becoming over-heated as it sits directly on the heat source.

The cleaning kit does include a stir tool to help mitigate the risk of overheating your herbs, but having to turn off the vape and stir up the material in the device’s heat chamber after each 2-minute session (especially when on the go) was a little annoying and is simply too tedious for heavy-use vaporists like myself.

Review: The New G Pen Pro Portable Vaporizer from Grenco Science

What’s Included with the G Pen Pro Vaporizer

Open the G Pen Pro packaging and you will find:

  • 1 G Pen Pro vaporizer
  • 1 USB/Mini-USB charging cord
  • 1 cleaning brush
  • 1 G Pro tool

How to Use The G Pen Pro Vaporizer

To fill the G Pen Pro vaporizer, remove the plastic mouthpiece by popping it off with your fingers to reveal a small chamber. Grind your dried herb material (not too fine, but not too chunky), and pour it in to the herb chamber. Lightly tap down the material, but be careful not to over pack or it will restrict the device’s airflow and leave you dissatisfied with your session.

Something that may mix up new users is that the mouth piece is actually two separate but connecting pieces: a small rubber cap and a hard-plastic piece. Both should stay snapped together while removing the mouthpiece, if you take them off separately and put them back on separately, the rubber cap will not fit correctly.

To turn on the G Pen Pro vaporizer, simply tap the power button with a leaf on it five (5) times. When done correctly, the device’s LEDs will light up to the last-selected temperature setting.

The G Pen Pro has three preset temperature settings to choose from:

  • Blue: 375 F | 190 C
  • Green: 400 F | 204 C
  • Red: 428 F | 220 C

To select your desired temperature setting, press and hold the leaf button for five (5) seconds until you see the LEDs change colors to the next temperature setting. Continue to toggle through the different heat settings until you’ve selected your desired temperature. From here, the LEDs should be glowing, which signifies that the G Pen Pro herb chamber is heating up to the selected temperature. The LEDs will turn solid and quit blinking once the unit is pre-heated and ready for you to begin taking draws from the mouthpiece.

From my experience, the green temperature setting (400 F | 204 C) consistently generated the best results / most vapor. It takes roughly 15 – 30 seconds for the pen to reach the selected temperature setting (depending on the heat setting) which is certainly an improvement over the 60 – 90 seconds heat up time from its predecessor). However, you should know that it typically takes at least two to three draws (long inhales) until the herb in the chamber gets hot enough to produce vapor that you can see when exhaling. If you think the unit is not working, keep going and see how you feel after the unit heats up more and you take a few more draws.

Review: The New G Pen Pro Portable Vaporizer from Grenco Science

Charging the G Pen Pro Vaporizer

The Grenco website states that it takes between 2 and 3 hours to fully charge the 2200mAh / 7.77Wh, 3.7-4.0V lithium-ion battery. We found this to be accurate, with a time closer to 2 hours when charging from a wall outlet. The four LED lights on the vape display the remaining battery life. When all LEDs are lit, the pen is fully charged. When there are less than two LEDs lit, the G Pen Pro should be charged.

The USB/mini USB cord can connect into a computer port or an adapter for a wall outlet. While the device is charging you get to enjoy a 4th color setting: turquoise!

For its price point, the battery life for the G Pen Pro is pretty good. We averaged about 8 long sessions (2 minutes per session), with 10+ draws per session. When doing this, the batteries would last roughly a day and a half on a single charge.

After trying a few different set-ups, we found that lightly packing to the top of the stainless-steel chamber with larger crumbs, combined with long slow inhales, gave the best results for vape flavor. We let the temperature sit at the green color and would get 6 or 7 nice long drags until jumping to the red setting after that for 3 or 4 more hits. The flavor quality dropped with more hits and had a strong popcorn flavor in the red setting.

The G Pen Pro Vaporizer: Final Thoughts

Although the G Pen Pro does what it sets out to do, it’s really nothing to get that excited about. The vaporizer essentially holds the same set of pros and cons as we outlined for its predecessor, the G Pro Herbal vaporizer. On one hand, the unit’s extended battery life, discrete design, and cheap price tag of $99.95 are strong selling points for someone looking to vape on the go. On the other hand, the G Pen Pro’s fast-clogging mouthpiece, inferior construction materials, and lackluster draws of vapor leave much more to be desired, especially for daily users.

I’d be hard-pressed to recommend the G Pen Pro for more sophisticated, dedicated vaporists when there are so many options on the market. For those seeking a long-term investment, it may be worth the extra cash to upgrade to a well-constructed stationary convection vaporizer (e.g., bag/whip style).

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FOOD AND DRUG ADMINISTRATION (FDA) DISCLAIMER - These statements have not been evaluated by the Food and Drug Administration (FDA). These products are not intended to diagnose, treat, cure, or prevent any disease.


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