Last Updated on May 2, 2026 by Sanjana Kahol
Cannabis has been studied for many years. Most of the work has focused on THC and CBD. These are the compounds that get the most attention because of their effects on the body and mind. But a new study shows that the plant has many more secrets than people thought. Scientists have just found dozens of new compounds in cannabis leaves, and a few of them are very rare in nature.
The discovery is changing the way researchers think about this plant. It also points to a side of cannabis that the medical world may have been missing: the leaves.
A surprise in the leaves
Researchers at Stellenbosch University in South Africa looked at three types of cannabis. They tested both the flowers and the leaves of each strain. The flowers usually get all the focus because that is where most of the THC and CBD are. But this team wanted a fuller picture.
They used a powerful tool called two-dimensional liquid chromatography paired with high-resolution mass spectrometry. That is a long name for what is basically a very sharp chemical microscope. It can separate and identify compounds that older methods miss. With this method, the team found 79 phenolic compounds in the plant samples.
Phenolic compounds are a big and important group of plant chemicals. They include flavonoids, which are common in fruits, vegetables, and tea. Many phenolics act as antioxidants. They are studied for fighting inflammation, supporting heart health, and even slowing some cancers. Out of the 79 compounds found, 25 had never been reported in cannabis before. That alone makes the study a big find.
A rare class of molecules
The biggest surprise was a group called flavoalkaloids. These are very rare in nature. They are like a chemical hybrid. They mix the structure of flavonoids with the structure of alkaloids. Alkaloids are another large group of plant chemicals that include things like caffeine, morphine, and quinine.
Until now, no one had ever found flavoalkaloids in cannabis. This study found 16 of them. Most of them were hiding in the leaves of just one strain. The flowers had almost none. That is striking, because the cannabis industry usually treats leaves as waste. The flowers are dried and sold. The leaves are tossed.
The first author of the study, Magriet Muller, said that even her team was surprised. They expected cannabis to be chemically rich. They did not expect such a big difference between just three strains. The plant turned out to be far more complex than anyone had assumed.
Why this is exciting
Phenolic compounds are already known to be valuable in medicine and food science. They are part of why people talk about plant-based foods as helpful for long-term health. They are studied for fighting inflammation, helping the heart, and protecting cells from damage.
If cannabis leaves are full of new phenolics, the plant may have a much wider range of uses than the THC and CBD industries suggest. That is important for medical research. Many drugs we use today started life as plant chemicals. The list of natural molecules that could become tomorrow’s medicines just got longer.
The study also shows how complex plants really are. A single plant can make hundreds of different molecules. Many of them act in small but real ways on the human body. Many also work together. So focusing on just one or two compounds, like THC, can give us only a tiny part of the picture.
Waste turned into treasure
There is also a strong message about waste. Across the world, large amounts of cannabis leaf are thrown away every year. Farmers and producers see them as scrap. This study suggests that those leaves may carry compounds that could be turned into medicines, supplements, or research tools. With the right care, what is now waste could become a useful resource.
This pattern is not new in food and plant science. Grape skins, citrus peels, and coffee husks all turned out to hold useful compounds once people looked closely. Cannabis leaves may be the next item on that list.
Why the strain mattered so much
One of the most interesting parts of the study is how different the three strains were. The flavoalkaloids appeared mainly in just one of them. The other two had almost none. This shows that the genetics of the plant make a huge difference. Two cannabis plants can look almost the same on the outside but have very different chemistry inside. Growers and breeders have known this for a long time when it comes to THC and CBD. The study suggests that the same is true for many other compounds that no one has been tracking.
That has real consequences for medical research. If a compound only shows up in one strain, then the strain used in any future study will matter a lot. A clinical trial that uses the wrong strain might miss the very molecule that could help patients. It will likely push researchers to study the genetic and chemical fingerprints of each strain in much more detail before testing them in people.
What happens next
The researchers say a lot more work is needed. The 16 flavoalkaloids were only tentatively identified. Their exact structures need to be confirmed. Their effects on the body must also be tested. Some may have strong activity. Others may have very little. Only careful lab and clinical work will tell.
For now, the message is clear. Cannabis is more complex than we thought. The parts of the plant that get thrown away may be just as interesting as the parts we use. It is also a good reminder that even well-studied plants can keep surprising us, much like the hidden chemistry that scientists keep finding inside everyday foods.
Cannabis is no longer just a story about THC and CBD. It is starting to look like a much bigger natural pharmacy waiting to be explored.
Read the full study summary here: https://www.sciencedaily.com/releases/2026/05/260501002156.htm