My thoughts from reading both studies briefly was they saw an increase that was 1.2 out of 2 times recordable increase but couldn’t say what the increase was a result of due to variables that were not controlled or even accounted for, mainly temperatures. That seems like a huge oversight? I believe they had used clones but you cannot clone or replicate soil and and environmental conditions enough, or closely enough to have a definitive conclusion. It was a healthy discussion. Im running a UV currently and still wonder if it’s necessary? @Storm nailed it though. It will be difficult to get an honest outlook on it due to the inherent bias of the experiments purposes. Marketing will always say it’s a gain while detractors will perform an equal experiment with differing results. The differences in experiments betrays the ambiguity of the constants of control, or lack thereof. I’m guessing theres a ton of studies that one could go through? Even when science reaches it’s “facts”, its often soon overturned or rendered questionable due to new science and more data.
Ive read both studies more thoroughly, but not exhaustive. They both conclude that the number of variables are too immense to provide a truly scientific result.
Conclusion 2022 study
Conversely, we saw no commercially-relevant benefits to exposing cannabis plants to UV radiation. Given the myriad potential UV exposure algorithms (i.e., combinations of spectrum, intensity, and temporal application strategies) more research is needed to determine if and how UV exposure in indoor cannabis production may be a commercially-relevant production tool and elucidate appropriate treatment protocols for commercial applications
Conclusion 2019 study
The effects of near-visible light, especially UV, on yield require additional data to form conclusions. Light intensity studies have been conducted with conclusive results, but comparisons between studies are hampered by the differences in controlled variables between experiments. Optimal light conditions for cannabis should be researched under controlled environments to determine the optimized combination of light intensity with plant density for maximum plant yield.
I’m searching to see if there is anything more recent or peer reviewed. I dont see that either of these are outside their immediate reference group?
Was just shopping again last two days and now I’ma stop again 
Lol. Mine came with the light I bought so I’m utilizing it wondering if I’m lipsticking a pig or throwing mud on a supermodel?
Definitely utilize it buddy
I just found a 2024 that says they found a decrease in cannabinoids but a slight increase in one terpene. The thing with the studies is they all seem to accelerate the drying process with nitrogen or some other process. The most recent one I read pulverized the materials to analyze them. None of us would ever replicate these processes thereby invalidating the practical use of these studies to us. In conclusion, the light stays in my tent.
I just harvested my present grow I’ve done under an HLG 700 Rspec FR and HLG UVA 30 watt bar light. It was the first time I used UVA and I have the most aromatic buds that are very resinous and potent. It’s the best weed I grew so far. It was my 5th grow. The only 2 things I did differently this time was switched from soil to Promix and added UVA. I’m very happy with the buds. It’s just as good, if not better than any top shelf dispensary weed I can buy. I truly believe it was the addition of UVA that made these buds so good!
I value info like this above the controlled studies, that never come close to replication of the practices of a common grower.
I had to find out for myself. I’m curious like a cat when it comes to stuff like this. The UVA definitely affected my plants. I had 2 different strains, 3 different Peanut Butter Breaths and 1 Sweet Island Skunk that didn’t accept the UVA at all. It burned up and the buds are very larffy. It wouldn’t grow higher than one foot and it stopped growing and didn’t stretch in flower but what it did produce is very aromatic and potent. It’s more potent than the Peanut Butter Breaths that grew very healthy. I have trouble finding the right words and I’m not good at composing my thoughts into writings. Sorry for this at times like these. This is my 5th grow and most successful grow to date. First grow using UVA and Promix HP. Everything else stayed the same except the quality of the flowers that grew. For the first time did I grow good weed like I would buy from a dispensary or pay $300 an ounce for off the streets! I mean this stuff is fire. How else could I have done that without knowing exactly what I was doing without the UVA light? UVA, I believe, is the Silent Sentinel for added resin, terpense and THC production. They definitely need some radiation to throw their defenses up at. I’m sold on UVA. I am a believer. I’ve seen it ruin a plant to now, don’t forget. UVA is not good for every strain out there. Like @Venturi mentioned, some genetics are lost when they are crossbred with different strains and I’m sure that’s why my Sweet Island Skunk burned up the way it did. Any leaves that received the UVA directly burned up into a purple black crispy dead thing. It stopped growing once I turned the UVA on for flowering and it grew small larffy buds that are very potent and aromatic. It’s my best smoke. The Peanut Butter Breaths are just as good in every department. I mean they check off every box in the quality stats! Very aromatic and sticky resin. I bought a few extra UVA bars from HLG for back ups even. This is how sure I am that it was the UVA.
I’ve got this same light setup. Looking forward to the results. Im curious though, do you think the Promix was indifferent to your improved results?
You and just about everyone else here too. There is nothing special about most of the weed at dispensary.
Im currently doing a dissertation. Just wondering if you know of any studies on cannabis related stigma felt by medical patients. Moreso, between different types of patient. So, pain - mental health.
I’m surprised that one sentence in my summary of a literature review (which is itself a summary of many experiments) generated so much discussion.
I’m pleased with the quality of that discussion. @SausageMahoney even went so far as to read the lit review and the paper @dbrn32 referenced and post his own summary of the UVA findings.
Please provide the reference or link. I’m trying to collect all papers that have tested UVA.
“Scientific fact” is used with that meaning sometimes in the vernacular. You won’t find it used that way in scientific literature. An effect that’s been replicated many times would be termed “well-established” or a synonym.
You seem to think scientific research is funded by marketing departments and performed by lackeys who are obliged to produce whatever results marketing wants. Trade journals publish work like that. One purpose of peer review in scientific publishing is to screen it out.
This common perception is due largely to the way science gets reported to the public. It seems to me that what gets reported and how is influenced more by a desire for viewership than a desire to inform.
Reporting science to non-scientists is admittedly tricky, though. It didn’t occur to me, for example, that someone might think a single experimental result implies that UVA will produce a 62% increase in THC in all cases. No one who’s posted made that error but, apparently, others might.
Others do. It’s like buying seeds that list thc % thinking the seeds you purchased will produce the same. Happens often here, although thinking about it not as much as 5+ years ago.
To me, there are about 3 different types of non scientific people that will review scientific data. Those that are looking for something to support whatever they already believe. Those that are looking for examples to disprove someone else’s thoughts/ideas. And those interested enough to read and understand the material then see if it makes any practical sense on an individual application. I’m a lot more open minded to information that’s not gimmicky, like what is the ideal leaf surface temperature or best time to water. And very skeptical of anything trying to prove product or equipment.
100% agree with that. Ive had 3 grows tested for cannibanoids and terpines. The last one because it produces an outstanding head high. Was totally surprised because at 11% it gets me far more f-d up than my 23% one. So i dont care if i need an extra hit of great tasting weed. If all i cared about was the high id just do cartridges.
Yup. The new school hipster movement for ridiculously high thc missed this about cannabis.
When people ask me how high is the THC % of the cannabis I’m giving them, I always reply: “Oh, it should be around 25-27%”… Regardless of what I’m giving them. And I have no way of knowing since I don’t have a home tester… But they always love my weed and praise how high it gets them… 
Those are the people I’m hoping to serve by searching out and calling attention to relevant literature and findings from peer-reviewed journals.
@SausageMahoney Thanks for the link, but that’s the 2022 article @dbrn32 shared.
It seems to me that the focus on THC content has its origins in medical research. Controlled dosing is a key requirement and impossible to achieve by having test subjects smoke a joint. When THC was identified as the primary ingredient of interest, the dosage-control problem was solved, but medical research on cannabis changed to research on THC, and it’s taken a long time for the researchers to realize that THC isn’t the analogue for cannabis they first thought.