February 24, 2026

Jen Hight

THCA, THCA Legality

Is THCA Legal in Wisconsin? 2026 Complete Legal Guide 

THCA Legal Status in Wisconsin:

Yes, Hemp-derived THCA is legal in Wisconsin in 2026, with conditions. Wisconsin Statutes § 94.55 (Hemp), THCA products are legal at the point of sale if they contain less than 0.3% Delta-9 THC by dry weight. Wisconsin has not explicitly banned THCA by name.

In Wisconsin, hemp-derived THCA products containing less than 0.3% Delta-9 THC by dry weight are legal under Wisconsin Statutes § 94.55 (Hemp), the state’s hemp program statute, which is aligned with the federal 2018 Farm Bill. The state of Wisconsin has not explicitly banned THCA, and it does not appear on the list of controlled substances under current state law.

There is, however, more nuance to THCA’s legal status than a simple yes or no. The chemical process of converting THCA into Delta-9 THC takes place when it is heated, be it through smoking, vaping, or cooking. This process is called decarboxylation. At that point, enforcement authorities and testing agencies may view the product differently, especially since “total THC” calculations can push a product over the legal limit.

Wisconsin is also one of the more conservative states on cannabis broadly: recreational and medical marijuana remain prohibited, and state law continues to treat THC and its derivatives as controlled substances. This creates a complex environment where a product can be technically compliant on paper but still carry legal risk depending on how it is used and how law enforcement interprets it.

This guide breaks down everything Wisconsin residents and visitors need to know about THCA legality in 2026: the relevant state statutes, how testing works, what product types are available, the latest legislative developments, and how to buy with confidence.

Table of contents:

• Key Takeaways
• What Is THCA?
• Federal Law: The 2018 Farm Bill Foundation
• Wisconsin State Law: The Specific Statutes
• 2025–2026 Wisconsin Legislative Updates
• The Total THC Compliance Issue: What You Need to Know
• THCA Products Available in Wisconsin
• Why Choose ATLRx for THCA Products in Wisconsin?
• Summary: Is THCA Legal in Wisconsin?
• Frequently Asked Questions About THCA Legality in Wisconsin

Key Takeaways

• In Wisconsin, THCA must be hemp-derived and contain less than 0.3% Delta-9 THC by dry weight.
• In Wisconsin, there is no state ban on THCA, Delta-8, or other hemp-derived cannabinoids; however, once heated, THCA converts to THC through decarboxylation.
• The “Total THC” formula (Delta-9 THC + THCA × 0.877) is the critical compliance test — high-THCA flower may fail this threshold even if pre-heat Delta-9 levels appear compliant.
• Milwaukee enacted a local ordinance in 2025 restricting hemp-derived THC product sales to buyers 21 and older.
• Wisconsin removed marijuana reform from its 2025 state budget, signaling no near-term path to broader cannabis legalization.
• Coming in November 2026: Federal hemp rules will change the total THC calculation method, which will significantly affect the THCA market in Wisconsin and nationwide.
• Always verify products with a batch-specific Certificate of Analysis (COA) from a third-party lab before purchasing.

What Is THCA?

Tetrahydrocannabinolic Acid, or THCA, is a naturally occurring, non-psychoactive precursor to Delta-9 THC found in raw hemp and cannabis plants. In its unheated state, THCA does not produce intoxicating effects — it is only when heat is applied that the compound undergoes decarboxylation and converts into the psychoactive Delta-9 THC most people are familiar with.

This distinction is central to understanding THCA’s legal status. Because THCA in its raw form is not psychoactive, it occupies a different — and somewhat ambiguous — position under hemp and controlled substance laws compared to Delta-9 THC.

THCA vs. Delta-9 THC: Key Differences

Federal Law: The 2018 Farm Bill Foundation

The 2018 Agriculture Improvement Act, commonly called the Farm Bill, transformed the national hemp landscape by removing hemp from the federal Controlled Substances Act. Hemp is defined as Cannabis sativa L. derivatives containing less than 0.3% Delta-9 THC by dry weight.

THCA is not explicitly named in the 2018 Farm Bill, and because it is not Delta-9 THC in its raw form, hemp-derived THCA initially occupied a permissive space under federal law — provided Delta-9 THC levels in the product stayed under 0.3%.

However, the USDA introduced a critical testing requirement via 7 CFR § 990.1 that applies a specific formula to determine total THC compliance:

Total THC = Delta-9 THC + (THCA × 0.877)

The 0.877 factor accounts for the molecular weight loss that occurs when THCA converts to Delta-9 THC during decarboxylation. This formula means that even if a product’s raw Delta-9 THC level is below 0.3%, a high THCA concentration can push the total THC calculation over the legal threshold.

In practical terms, THCA flower with 20% THCA content would calculate a total THC of approximately 17.5% — far exceeding the 0.3% limit. This is the central compliance tension for THCA flower products specifically.

Wisconsin State Law: The Specific Statutes

Wisconsin codified its hemp program primarily through Wisconsin Statutes § 94.55 (Hemp), which aligns state hemp definitions with the 2018 Farm Bill. The relevant provisions also appear in Senate Bill 119, sections 94.67(15r) and 961.14(4)(t)1.

Key points of Wisconsin’s statutory framework:

• A hemp plant is defined as Cannabis sativa L. that contains no more than 0.3% Delta-9 THC by dry weight, in accordance with federal law.
• Wisconsin law does not explicitly list THCA as a controlled substance in its raw form.
• Wisconsin’s controlled substance scheduling does include THC and its analogs broadly, which creates ambiguity around THCA because of its potential to convert into Delta-9 THC.
• The state does not have a recreational or medical marijuana program (other than extremely limited CBD access under Lydia’s Law / Wisconsin Act 267 for specific seizure conditions).
• Wisconsin follows the USDA’s testing approach, meaning pre-decarboxylation testing determines initial compliance — but post-decarboxylation use is not explicitly protected.

The bottom line: THCA from compliant hemp is not a controlled substance in Wisconsin when purchased and possessed in product form. However, the moment a consumer heats and uses that product, it potentially falls into a legal gray area because the resulting THC levels may exceed state thresholds.

2025–2026 Wisconsin Legislative Updates

Wisconsin’s cannabis law landscape is actively shifting. Here are the key developments every THCA consumer and business in the state should know:

1. Cannabis Reform Removed from 2025 State Budget

Efforts to advance marijuana reform in Wisconsin were removed from the 2025 state budget, confirming that no near-term path to broader cannabis legalization exists at the state level. Wisconsin remains one of the stricter states on cannabis broadly.

2. Milwaukee’s Local Ordinance — Age Restriction for Hemp THC Products

In 2025, the City of Milwaukee enacted a local ordinance restricting the sale of hemp-derived THC products — including THCA products — to buyers 21 years of age or older. This is notable because Wisconsin state law does not set a specific age requirement for hemp purchases, making Milwaukee’s local rule more restrictive than the state baseline. Consumers and retailers in Milwaukee should treat 21+ as a hard requirement.

3. Federal Hemp Rule Change — Effective November 2026

A sweeping amendment to federal hemp definitions was passed by Congress on November 12, 2026. Under the new rules, the total THC formula (Delta-9 THC + THCA × 0.877) will become the federal standard for all hemp compliance determinations — not just for pre-harvest testing.

For THCA flower specifically, this means that high-THCA products that are currently sold as legal hemp will no longer qualify under the new federal definition if their total THC exceeds 0.3%. Wisconsin consumers and retailers should plan for significant changes to the THCA flower market by Q4 2026.

4. No Wisconsin-Specific THCA Legislation as of Early 2026

As of the date of this article, Wisconsin has not passed any laws specifically naming or restricting THCA by name. This leaves its legality tied to the broader hemp and THC frameworks described above. Consumers should monitor for any changes, as the state’s conservative cannabis stance could prompt targeted legislation.

The Total THC Compliance Issue: What You Need to Know

This is the single most important nuance for THCA purchasers in Wisconsin to understand. 

Here is how compliance testing works and where the gray area lies:

Pre-Decarboxylation Testing (Point of Sale Compliance)

When a THCA product is tested before being heated, the laboratory typically measures only the Delta-9 THC present in the raw product. If that level is below 0.3%, the product can be legally sold as hemp-derived in Wisconsin at the point of sale.

Post-Decarboxylation Risk (After Heating/Consumption)

When THCA flower or concentrate is smoked, vaped, or cooked, the THCA converts to Delta-9 THC. Under the total THC formula, a product with high THCA may produce Delta-9 THC levels that significantly exceed 0.3% — technically making the consumed form non-compliant, even if the product was purchased legally.

Wisconsin law does not explicitly protect consumers in this post-decarboxylation scenario. Law enforcement may treat high-THCA products similarly to marijuana — especially without documentation proving hemp origin.

The Practical Implication for Wisconsin Consumers

• THCA tinctures, edibles (unheated), and raw flower (unsmoked): Generally lower compliance risk — product stays below the legal threshold in its used form.
• THCA flower when smoked or vaped: Carries more legal risk because the conversion to THC during consumption can produce levels above 0.3%.
• Always carry your COA: If approached by law enforcement, a Certificate of Analysis showing compliant Delta-9 THC levels at the point of sale is your strongest documentation of compliance.

THCA Products Available in Wisconsin

Hemp-derived THCA products are legal in Wisconsin, provided they meet the 0.3% Delta-9 THC threshold. 

ATLRx carries a full range of these product types — all sourced from compliant hemp and third-party tested. You can view batch-specific Certificates of Analysis directly on the ATLRx lab results page before purchasing.

1. Verify it is hemp-derived: Confirm the product comes from legally grown hemp — not marijuana — with under 0.3% Delta-9 THC by dry weight.
2. Request a current COA: Ask for a batch-specific Certificate of Analysis from an accredited, independent third-party lab. Delta-9 THC should be below 0.3% on the COA, along with the total THC calculation.
3. Check the total THC calculation: Use the formula (Delta-9 THC + THCA × 0.877) to estimate whether the product would remain compliant under the total THC standard.
4. Buy from a reputable retailer: Choose established brands with transparent lab testing, clear product labeling, and a track record of compliance. Avoid unlabeled products or retailers who cannot provide COAs.
5. Always carry a copy of your documentation when carrying THCA products. This can be critical if law enforcement questions the product’s legality.
6. Observe local ordinances: If you are in Milwaukee, remember the 21+ age requirement for hemp-derived THC products. Other municipalities may adopt similar rules — check local regulations in your area.
7. Stay informed: Wisconsin THCA law is evolving. Bookmark reliable sources and check for updates — especially as the November 2026 federal rule changes approach.

Why Choose ATLRx for THCA Products in Wisconsin?

ATLRx is a Georgia-based hemp retailer with years of experience sourcing compliant, high-quality hemp products and shipping to customers nationwide, including Wisconsin. Here is what sets ATLRx apart for Wisconsin shoppers:

• Full COA transparency: ATLRx THCA products are tested by independent, accredited laboratories. Our lab results page includes COAs so you can verify them before you buy.
• 2018 Farm Bill compliance: All ATLRx THCA products are sourced from hemp cultivated within federal legal limits — Delta-9 THC under 0.3% by dry weight.
• Wide product selection: From THCA flower and pre-rolls to vape carts, concentrates (diamonds, badder, crumble, isolate), ATLRx offers one of the most comprehensive THCA product ranges available online.
• Ships to Wisconsin: ATLRx ships hemp-derived THCA products to Wisconsin. Federal compliance documentation ships with your order.
• Established reputation: ATLRx has served thousands of customers with verified reviews and a commitment to quality that begins at the source.

Summary: Is THCA Legal in Wisconsin?

In Wisconsin, hemp-derived THCA is legal under Wis. Stat. Under 94.55 and the 2018 Farm Bill, products must not contain more than 0.3% Delta-9 THC by dry weight. Wisconsin has no specific ban on THCA, and it is not listed as a controlled substance in its unheated, hemp-derived form.

That said, Wisconsin’s conservative cannabis framework and the chemical reality of decarboxylation create genuine compliance complexity — especially for THCA flower when smoked or vaped. The approaching November 2026 federal hemp rule changes will tighten the total THC standard further, making compliant sourcing and clear COA documentation more important than ever.

For Wisconsin consumers, the path to buying and using THCA responsibly is clear: choose reputable, transparent retailers, verify COAs, carry your documentation, and stay informed as laws continue to evolve.

ATLRx offers a full range of third-party tested, Farm Bill-compliant THCA products available for delivery to Wisconsin. Browse our THCA collection or review our lab results before you order.

Frequently Asked Questions About THCA Legality in Wisconsin

Is THCA Legal in Wisconsin in 2026?

Yes. Hemp-derived THCA products containing less than 0.3% Delta-9 THC by dry weight are legal under Wisconsin Statutes § 94.55 (Hemp), consistent with the 2018 Farm Bill. However, the legal picture becomes more complex once THCA is heated and converts to Delta-9 THC. Always carry your COA as proof of compliance.

Is THCA a Controlled Substance in Wisconsin?

THCA in its raw, hemp-derived form is not explicitly listed as a controlled substance under Wisconsin law as long as the product complies with the 0.3% Delta-9 THC threshold. However, Wisconsin’s broader controlled substance laws cover THC and its analogs, which can create ambiguity around THCA’s post-decarboxylation status.

Can I Buy THCA Flower in Wisconsin?

Yes. THCA flower that is hemp-derived and contains less than 0.3% Delta-9 THC at the point of sale can be legally purchased in Wisconsin. Compliant products are available from licensed online retailers like ATLRx, as well as select local hemp shops. Always verify with a COA.

Is Smoking THCA Flower Legal in Wisconsin?

This is the gray area. The product itself may be compliant at purchase, but smoking or vaping THCA converts it to Delta-9 THC. The resulting THC levels from high-THCA flower can far exceed 0.3%, which Wisconsin law would treat as a controlled substance. It may be difficult for law enforcement to distinguish between hemp-derived THCA smoke and marijuana smoke without lab testing. Carrying your COA is strongly recommended.

Can I Have THCA Products Shipped to Wisconsin?

Yes. As a result of the 2018 Farm Bill, hemp-derived THCA products can be shipped to Wisconsin from online retailers. ATLRx ships compliant THCA products to Wisconsin with documentation included.

Will THCA Show up on a Drug Test?

Yes. THCA and Delta-9 THC are both metabolized into THC-COOH, the metabolite standard drug tests screen for. THCA products can result in positive drug test results, even in their unheated form. In the event that you are subject to workplace or legal drug testing, exercise caution.

What Is the Age Requirement to Buy THCA in Wisconsin?

Wisconsin state law does not set a specific age requirement for hemp purchases. Many retailers restrict the sale of THCA products to customers 18 or 21 years of age or older. In Milwaukee, a local 2025 ordinance requires purchasers to be 21 or older for hemp-derived THC products.

Is There a Possession Limit for THCA in Wisconsin?

Wisconsin does not impose specific possession limits for compliant hemp-derived THCA products. However, since the line between legal hemp and illegal marijuana can be difficult for law enforcement to assess in the field, keeping quantities reasonable and carrying documentation is advisable.

Can I Travel with THCA Products Through Wisconsin?

Traveling within Wisconsin with compliant hemp-derived THCA products is generally permissible. Keep your COA accessible. Note that crossing into states where THCA is explicitly restricted (such as Idaho or Oregon) with these products creates separate legal risks.

What Is the Total THC Formula, and Why Does It Matter for THCA?

The total THC formula — Total THC = Delta-9 THC + (THCA × 0.877) — calculates how much Delta-9 THC a product could produce if all its THCA were converted through heat. A product with high THCA (like 20% THCA flower) would calculate a total THC of about 17.5%, which is far above the 0.3% legal threshold. This formula is used in USDA compliance testing and will become the federal standard under the November 2026 hemp rule changes.

How Do I Verify a THCA Product Is Compliant in Wisconsin?

Check the product’s Certificate of Analysis (COA) with a third-party laboratory.

The COA should show:

• Delta-9 THC below 0.3% by dry weight,
• The testing lab’s accreditation,
• The batch or lot number matches your product
• Ideally, a total THC calculation.

Will Wisconsin Legalize Marijuana Soon?

As of early 2026, Wisconsin has not legalized recreational or medical marijuana, and cannabis reform was removed from the state’s 2025 budget. While public support for legalization has grown and neighboring states like Illinois and Michigan have moved forward, there is no clear near-term path to legalization in Wisconsin.