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What Is PGR Cannabis?

comparison of with PGRs and without PGRs weed

PGR weed is cannabis grown with plant growth regulators. Some cannabis growers raise PGR (plant growth regulator) crops to enhance growth patterns and fatten up valuable marijuana buds. PGR buds are thicker and denser than those grown without plant growth regulators.

But these plant hormones are not the best way to achieve a healthy cannabis yield. The visual appeal of PGR-grown cannabis is offset by its lack of trichomes, cannabinoids, and terpenes.

There are also natural types of PGRs that can be successfully used in place of synthetic ones. For example, cannabis cultivators can use kelp or chitosan and achieve the same impressive results as synthetic plant growth regulators. Natural or organic plant growth regulators present the bonus of environmental friendliness and safety for human consumption.

The use of PGRs often occurs on the unregulated black market. Synthetic PGRs can be harmful to human health and may even cause cancer.

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How to Recognize PGR Cannabis

The main difference between PGR cannabis and natural cannabis is that PGR cannabis is grown with synthetic hormones, while natural cannabis is not. Plant growth regulators in PGR cannabis also lend a different appearance to crops. Here are some ways you can distinguish between PGR cannabis and natural cannabis:

  • PGR cannabis has harder, denser, and heavier buds.
  • PGR cannabis leaves contain fewer crystals than natural cannabis leaves.
  • PGR cannabis may feel wet or spongey, while natural cannabis has a drier texture.

Another way to tell PGR cannabis from natural cannabis is to break off a piece. Natural cannabis is fragrant with terpenes and flavonoids, but PGR cannabis has very little scent. Likewise, the taste of PGR marijuana is inferior to the rich flavors of natural marijuana. A telltale sign of PGR cannabis is a harsh, chemical-laced flavor.

Finally, PGR cannabis may make you feel different when you consume it. This difference is due to the lower THC content of PGR weed and the PGR chemicals themselves, and PGR chemicals may quickly intoxicate you and cause a “crash” in which you feel lethargic and heavy-headed.

Types of Synthetic PGRs Used When Growing Cannabis

Different types of PGRs may be used to grow cannabis. The most common types of PGRs are chlormequat chloride, daminozide, and paclobutrazol.

Chlormequat Chloride

This chemical encourages flowering and makes plant sizes more uniform and consistent. Chlormequat chloride may not be as carcinogenic as other synthetic plant growth regulators but may cause harm to the skin and eyes if contact is made.


Also called Alar, the Environmental Protection Agency (EPA) classified daminozide as a probable carcinogen. Once used as a spray for fruits, vegetables, and other food crops, daminozide may no longer be used for this purpose.


Paclobutrazol may be the most toxic of these three common chemicals, especially when smoked. Smoking buds containing paclobutrazol activate a chemical change that transforms the compound into nitrosamines, and research has implicated nitrosamines in developing severe illnesses. Notably, nitrosamines are a highly carcinogenic compound in tobacco (cigarette) smoke.

Is PGR Cannabis Safe to Consume?

PGR cannabis, made with synthetic plant growth hormones, has been linked to adverse health effects, including increased cancer risk. Synthetic PGRs may be carcinogenic and therefore are not appropriate for human consumption, and cannabis made naturally or with natural PGRs does not pose the same health risks.

Besides being potentially carcinogenic, synthetic PGRs may present the following health hazards:

More research is needed on the potential health risks of synthetic PGRs. To be safe, know the origin of the cannabis you consume and only purchase products from reputable growers who use sustainable practices.

Consume cannabis safely and responsibly with a medical marijuana card. Schedule an online appointment with one of Leafwell’s qualified medical professionals and get started on your application.

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Frequently Asked Questions

Is PGR illegal?

Due to their potentially cancer-causing properties, PGRs were made illegal in the food industry in 1999. Nutritional scientists have deemed that PGRs are unsafe for human consumption and thus banned them from being used in food crops. However, PGRs have not been banned from being used as fertilizers for ornamental plants.

How to tell if a cannabis product contains PGR weed?

You can tell if a raw cannabis product contains PGRs by the texture (spongy and wet) along with excessive amounts of brown or red hairs on the bud. When you consume a cannabis product like vapes or edibles made with PGRs, you may smell or taste chemicals rather than the rich aromas and flavors accompanying natural weed.

What does PGR cannabis do to the body?

Synthetic PGRs can cause a host of problems for the human body ranging from minor skin irritation to possible liver damage or failure. Some research has also indicated that PGRs are carcinogenic (may cause cancer) and should be considered toxins.

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