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What are Plant Growth Regulators and How Safe are They?

Chane Leigh

by Chane Leigh

June 21, 2023 09:30 am ET Estimated Read Time: 7 Minutes
What are Plant Growth Regulators and How Safe are They?

​With PGR weed growing in popularity, staying safe is the highest priority.

Ponder this… How much do you know about the cannabis you consume? Do you know how it was grown and what was used while it was growing? Do you know who the grower is and where it was grown?

It may surprise you that many people are unable to answer these questions. However, when it comes to cannabis, thorough understanding and context are everything. Some growers even treat cannabis buds with plant growth regulators (PGRs). We often purchase or opt for more dense buds, and chances are that those buds have been exposed to PGRs.

  1. What is PGR Cannabis?
  2. Is PGR Weed Safe to Consume?
  3. How Do PGRs Affect the Cannabis Plant?
  4. How to Identify PGR Weed

What is PGR Cannabis?

PGR cannabis is grown with plant growth regulators. Cannabis growers generally use PGRs to produce higher yields and fatter nugs.

PGRs, Plant Growth Regulators, are any substances, fertilizers, or mixtures which can be used to speed up or slow down the rate of growth in plants and food crops by targeting physiological actions that then change the natural behavior of the plant. Naturally, when we move away from the path of nature, there tend to be some effects- depending on the product. Cannabis cultivation is challenging as it is, so growers often make use of products or substances to enhance and grow better cannabis plants.

The main function of PGRs is to mimic or inhibit the plant’s normal growth hormones during the growth cycles. PGRs can have an impact on when fruits ripen and also on the length, width, and shape of the plant’s roots, stems, trichomes, and leaves. It’s time consumers start asking the right questions to ensure not only the best value for their money but, more importantly, to minimize health risks.

For cannabis, PGRs are likely commonly used to increase the plant’s health and resistance to fungus but often at a cost of flavor and visual appearance. More extreme risks of PGR cannabis include risks of organ damage, cancer, and infertility. They can also cause more minor health effects, like skin or eye irritation.

But can the same be said for all PGRs? Are all the substances this risky?

In short, no. Not all PGRs are harmful–but they can produce cannabis that is less safe to consume.

Is PGR Weed Safe to Consume?

Just like with cannabinoids, there are naturally-derived PGRs—but there are also synthetic PGRs. The sad reality behind PGRs is that they are often being used by growers who care less about harm and more about the money they will be getting from selling the “boosted” buds.

Luckily, the risks associated with PGR cannabis are fairly well-known. In fact, many plant growth regulators are banned for most crops, including within the cannabis industry. That’s why PGR use is more frequently seen on the black market and is unsuitable to serve as medical cannabis.

Why You Should Get Your Medical Marijuana Card

Veriheal has satisfied millions of patients nationwide by giving them access to these benefits

  • Larger purchase limits
  • Peace of mind
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  • Access to higher potency strains
  • Save up to 25% on cannabis purchases
  • Skip the line at the dispensary

Particularly, consumers should keep an eye out for synthetic PGRs, as they can impact liver function, leading to liver damage or failure.

Synthetic Types

When you see the words synthetic before anything, you should already be approaching with caution. Synthetic means that it was man-made using chemicals, compounds, or materials that imitate natural products for human consumption. If we have learned anything at all about the difference between synthetic and organic products is that the synthetic versions are often accompanied by less effective as well as adverse or undesired side effects. With that in mind, let’s have a look at some of the synthetic PGRs on the market:

  • Paclobutrazol
  • Daminozide (also called alar)
  • Chlormequat Chloride

In a not-so-unexpected shift of events, these synthetic PGRs are bad for our environment. Additionally, the Environmental Protection Agency (EPA) recently identified daminozide as a probably carcinogen.

The residual PGRs in the soil and water can cause some serious damage to the fish and waterways. Additionally, growing cannabis has been known to boost biodiversity in the soil but when synthetic plant growth regulators are used, biodiversity becomes negatively impacted.

Organic Types

As mentioned before, not all types of PGRs are harmful or dangerous but most of the PGRs being used are synthetic- which is dangerous and harmful. Organic PGRs such as those listed below, are naturally found in our atmosphere and are not risk or problematic to use- plus the fact that organic PGRs will boost your plant with the only extra cost being to your wallet. Wouldn’t you want to make use of a PGR that is best for your plants and for its consumers? Natural PGRs include:

  • Chitosan
  • Triacontanol
  • Kelp

The reason why people are interested in PGRs is pretty obvious. Bigger buds mean more revenue. But it’s often the case that people forego safety and health in pursuit of more profit. Do not be afraid to ask and inquire about the nature of your product’s growth. Ask the questions before you run the risk of suffering the consequences to your health.

However, if you were to use an organic PGR, which may cost you more money but still bring in more clients, your cannabis plants will still benefit from being naturally boosted without the looming worry which often accommodates synthetic PGRs. These plant growth regulators are so commonly used, that the best question may not be whether PGRs are being used, but rather whether what PGR is organic or synthetic.

How Do PGRs Affect the Cannabis Plant?

How is it that PGRs can have such an impact on buds? Well, simply put, the PGRs have an impact on the phytohormones-which are the plants’ hormones. These phytohormones play a key role in the growth and development of the plant. The plants’ hormones are also regulated naturally through environmental cues, receptors, and genome. The five major phytohormone classes include gibberellin, auxin, cytokinin, ethylene, and abscisic acid. PGRs are used to manipulate those hormones. 

The growth process is divided into stages where each of these hormones serves an important purpose.

Phytohormone Growth Stage
Gibberellin Gibberellin impacts the most during the germination, growth to maturity, and flowering stages with less of an impact, but still an impact, on the fruit development stage. 
Auxin & Cytokinin Auxin and Cytokinin impact the most during the growth, maturity, flowering, and fruit development stages. 
Ethylene Ethylene impacts the most during the flowering and fruit development stages and then again after the seed dormancy stage in the abscission stage.
Abscisic Acid Abscisic acid (ABA) impacts the most during seed dormancy and abscission (when ripe fruit drops). 

Phytohormone Growth Veriheal

How to Identify PGR Weed

Though PGR cannabis is impossible to spot without proper chemical testing, there are a few tell-tale signs to flag for at your local dispensaries.

  • Denser nugs – Cannabis plants grown with PGRs are super dense and tightly curled. PGR buds will be elongated and feel thicker than healthy, leafy buds, with a spongy consistency. They’re also rock hard, so they’ll feel weighted than healthy nugs.
  • Orange or red hue – PGR cannabis will have more brown and red hairs than naturally-grown cannabis. Coupled with the yellow-brown trichomes typical of PGR weed, the red and brown hairs will cause the flower to have a duller, orange or brown appearance.
  • Weaker smell – Not only are the trichomes a yellow-brown color, but there are also fewer trichomes on PGR cannabis. Because trichomes produce the plant’s terpenes, PGR weed will have a weaker smell and a chemical taste compared to natural cannabis.

Generally, PGR weed also has a lower CBD and THC content than other cannabis products, as the synthetic chemicals disrupt the production of the plant’s cannabinoids.

Post Your Comments

Mike Gintoli says:

October 3, 2022 at 7:02 pm

Great article! I suspect that the medical suppliers in Connecticut are using some version of PGR.
Can organic pgr be detected by testing?


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