Hemp chemistry • testing • product safety
Synthetic, Semisynthetic & Converted Cannabinoids in Hemp Products
“Synthetic,” “semisynthetic,” “converted,” and “naturally occurring” describe different things. This guide separates those terms, summarizes what FDA and published analytical studies actually show, explains the limits of Certificates of Analysis, and adds a firsthand Kentucky hemp manufacturing perspective.
Scientific source credentials
Chemistry and toxicology expertise behind the cited evidence
Robert M. Strongin, PhD, Professor of Organic Chemistry at Portland State University, coauthored peer-reviewed work on cannabinoid acetate chemistry and ketene formation during vaping.
Irfan Rahman, PhD, Dean’s Professor of Environmental Medicine at the University of Rochester Medical Center, coauthored a peer-reviewed analysis of commercial delta-8 vaporizer products that examined labeling, reaction side-products, cutting agents, and heavy metals.
Terminology
Do not collapse these categories
| Term | Meaning | Example / limit |
|---|---|---|
| Naturally occurring phytocannabinoid | Produced by the cannabis plant and detected in plant material or extract without first being created through conversion. | CBD and delta-9 THC are established examples. Natural occurrence does not by itself establish safety. |
| Naturally occurring at trace or very low levels | Reported in the plant at low concentrations that may be impractical to isolate commercially from biomass. | FDA says delta-8 THC occurs naturally but is not found in significant amounts. THCP has also been identified as a phytocannabinoid, but a “THCP” label alone does not disclose how a commercial ingredient was sourced. |
| Converted cannabinoid | A manufacturing description for a cannabinoid made by chemically changing another cannabinoid or cannabinoid-rich starting material. | CBD can be converted by acid-catalyzed cyclization into mixtures containing delta-8 and delta-9 THC. “Converted” describes process history, not a complete toxicology conclusion. |
| Semisynthetic cannabinoid | A chemistry term used for compounds produced by chemically modifying a naturally derived phytocannabinoid precursor. | Peer-reviewed literature commonly discusses HHC and related compounds in this category. |
| Fully synthetic cannabinoid | A cannabinoid or cannabinoid-receptor-active compound made through chemical synthesis rather than extracted from a plant precursor. | K2/Spice-type synthetic cannabinoid receptor agonists are a different category from CBD-derived delta-8 or natural full-spectrum hemp extract. |
Conversion chemistry
What the evidence supports
Delta-8 THC
FDA states that delta-8 THC occurs naturally at very low levels and that concentrated commercial amounts are typically manufactured from hemp-derived CBD. Peer-reviewed chemistry describes acid-catalyzed CBD cyclization as a route that can generate delta-8 THC along with other cannabinoids and reaction products depending on conditions.
HHC
A peer-reviewed review describes large-scale HHC manufacture from hemp-derived CBD through THC intermediates followed by catalytic hydrogenation to HHC epimers. Human pharmacology and long-term toxicology remain incompletely characterized.
THC-O / cannabinoid acetates
THC-O is an acetate derivative produced by chemical modification. Laboratory studies have shown ketene formation when cannabinoid acetates are heated under vaping conditions. That finding is route-specific and should not be generalized to every form of exposure.
Product-testing evidence
What sampled commercial products showed
These studies document problems in the products they tested. They do not prove that every converted cannabinoid product contains the same impurities.
27 delta-8 vape products
Meehan-Atrash and Rahman used NMR, GC-MS, and ICP-MS. In their sample, none had accurate delta-8 labeling; 11 contained unlabeled cutting agents; and the authors reported reaction side-products and heavy metals.
10 delta-8 products
Ray and colleagues used NMR, HPLC, and mass spectrometry and reported several impurities not reflected on the products’ COAs. Their work also illustrates that routine cannabinoid testing may not identify every unexpected compound.
20 retail delta-8 products
An independent analysis found wide variation between labeled and measured delta-8 THC content, with delta-9 THC detected in some samples. The results support verification without assuming every product or laboratory has the same accuracy problem.
FDA manufacturing concern
FDA warns that delta-8 conversion can involve chemicals that may create potentially harmful by-products and that uncontrolled manufacturing may add contaminant risk.
Testing and COA limits
A COA is only as broad as the testing performed
| Area | What a report may verify | Limit |
|---|---|---|
| Cannabinoid identity / potency | Reported cannabinoids and measured concentration. | Only analytes the method can resolve and quantify; unknown compounds or closely related isomers can require different methods. |
| Residual solvents | Whether listed solvents met the laboratory’s stated limits when that panel was performed. | A potency-only panel does not establish residual-solvent results. |
| Heavy metals | Whether tested metals met stated limits for that sample. | Use “tested for and met the laboratory’s stated limits” rather than an absolute “heavy-metal free” claim. |
| Pesticides / microbials | Results for the analytes actually included in the panel. | Panels vary; do not assume “full panel” means the same thing at every laboratory. |
| Conversion by-products | Known by-products if the method specifically includes them or broad characterization is performed. | Routine potency testing may not identify every unexpected reaction product. |
Firsthand manufacturing perspective
Bill Polyniak on manufacturing and testing
“Since 2014, my work has put me directly in hemp cultivation, extraction, formulation, manufacturing, in-house testing, third-party laboratory testing, batch documentation, and customer questions.”
“That experience taught me not to use a chemistry buzzword as a substitute for manufacturing evidence. A chemical conversion is not automatically unsafe simply because chemistry is involved. The practical questions are whether the process is controlled, whether process chemicals and side-products are removed or limited, whether the final material is characterized with suitable methods, and whether the published testing actually matches the finished batch.”
“A potency panel is also only a potency panel. If a report does not test residual solvents, heavy metals, pesticides, microbials, or conversion by-products, it should not be described as proving those things are absent. At Kentucky Cannabis Company and Bluegrass Hemp Oil, our focus has been plant-derived full-spectrum hemp, documented batches, clear labels, and testing transparency rather than manufacturing intoxicating converted-cannabinoid products.”
Bill is speaking from hemp cultivation, manufacturing, formulation, and product-testing experience—not as a clinical toxicologist.
FAQ
Common terminology and testing questions
Is delta-8 THC natural or synthetic?
The molecule has been reported in cannabis at very low levels. FDA says concentrated commercial delta-8 is typically manufactured from hemp-derived CBD. It is more precise to distinguish natural occurrence from the manufacturing source of a finished product.
Does semisynthetic mean the same thing as fully synthetic?
No. Semisynthetic generally describes chemical modification of a naturally derived precursor. Fully synthetic cannabinoid receptor agonists such as K2/Spice-type compounds are a different category.
Does a COA prove there are no reaction by-products?
No. A COA reports the tests actually performed. Routine potency testing may not identify every unexpected conversion by-product, so the analytes, method, scope, and reporting limits matter.
Do impurity studies prove every delta-8 product is contaminated?
No. The cited studies found issues in the products they sampled. Those findings justify careful process control and testing, but they should not be generalized to every product.
Primary and peer-reviewed evidence
Sources supporting this page
Evidence limit: Product-testing studies are snapshots of specific samples. They show that particular impurities, label discrepancies, and analytical limitations can occur; they do not establish that every product contains the same contaminants or by-products.
