Ketamine is a Schedule III controlled substance under Colorado law and under federal regulations. It is legal to use in therapy when a licensed practitioner prescribes or administers it for medical treatment. Outside that setting, Colorado treats ketamine more harshly than most Schedule III drugs: possessing any amount without authorization is a felony, even on a first offense. The criminal rules are not a gray area. Questions about treatment protocols and insurance coverage are matters of medical practice and insurance contracts, not criminal law.
Key Takeaways
- Ketamine is listed in Colorado’s Schedule III and in the federal Schedule III.
- Ketamine therapy is legal when a licensed practitioner administers ketamine directly or prescribes it, for medical treatment in the ordinary course of the practitioner’s profession.
- A patient may lawfully possess ketamine that was prescribed or dispensed to them, but only in the container it came in.
- Possessing any amount of ketamine without authorization is a level 4 drug felony in Colorado. Possessing most other Schedule III drugs is a level 1 drug misdemeanor.
- Giving ketamine to someone without their knowledge is a class 3 felony, unless it is given for bona fide medical needs by someone licensed to do so.
What Colorado Law Provides
- Ketamine is a Schedule III drug. Colorado lists “Ketamine, its salts, isomers, and salts of isomers” in Schedule III, C.R.S. 18-18-205(2)(g). Federal regulations also list ketamine in Schedule III, 21 CFR 1308.13(c)(7).
- Who may give it. A “practitioner,” which Colorado defines to include a physician, dentist, pharmacist, hospital, or other person licensed, registered, or otherwise permitted by the state to dispense or administer a controlled substance, C.R.S. 18-18-102(29). Anyone who dispenses a controlled substance in Colorado must hold a registration or license, C.R.S. 18-18-302(1).
- For medical treatment only. A practitioner may dispense or deliver a controlled substance “only for medical treatment or authorized research in the ordinary course of that practitioner’s profession,” C.R.S. 18-18-308(5).
- Prescriptions. A Schedule III drug may be dispensed to a patient only on a written, oral, or electronic prescription, but a practitioner other than a pharmacy may dispense it directly without one. A Schedule III prescription cannot be filled or refilled more than six months after it was written, or refilled more than five times, C.R.S. 18-18-308(4).
- The patient’s own supply. A person who was prescribed or dispensed ketamine may lawfully possess it, but only in the container it was delivered in, unless the person can show they are the legal owner. Violating this rule is a drug petty offense with a fine of up to $100, C.R.S. 18-18-413.
- Possession without authorization. Possessing any amount of ketamine is a level 4 drug felony, C.R.S. 18-18-403.5(2)(a).
- Selling or sharing. Distributing, selling, dispensing, manufacturing, or possessing ketamine with intent to distribute is a drug felony graded by weight, C.R.S. 18-18-405(2).
- Giving it to someone without their knowledge. Knowingly causing another person to unknowingly consume or receive ketamine is a class 3 felony, C.R.S. 18-13-123.
The penalty ranges come from C.R.S. 18-1.3-401.5(2) for drug felonies and C.R.S. 18-1.3-401 for the class 3 felony:
| Conduct involving ketamine | Offense level | Presumptive prison range |
|---|---|---|
| Possessing any amount without authorization | Level 4 drug felony | 6 months to 1 year |
| Sharing 2 grams or less to use together at the same time | Level 4 drug felony | 6 months to 1 year |
| Distributing 7 grams or less | Level 3 drug felony | 2 to 4 years |
| Distributing more than 7 grams, up to 112 grams | Level 2 drug felony | 4 to 8 years |
| Distributing more than 112 grams | Level 1 drug felony, with mandatory sentencing | 8 to 32 years |
| Giving ketamine to someone without their knowledge | Class 3 felony | 4 to 12 years |
The aggravated ranges are higher: 1 to 2 years for a level 4 drug felony, 4 to 6 years for level 3, and 8 to 16 years for level 2. A level 4 drug felony also carries a possible fine of $1,000 to $100,000. An adult who transfers any amount of a Schedule III drug to a minor who is at least two years younger commits a level 2 drug felony, C.R.S. 18-18-405(2)(b)(II).
What Is Ketamine and How Is It Used in Therapy?
How does ketamine function within therapeutic contexts? Ketamine, originally developed as an anesthetic, has gained recognition as an alternative treatment for various mental health disorders, particularly treatment-resistant depression. Its mechanism involves antagonism of NMDA receptors, leading to rapid modulation of glutamate neurotransmission and synaptic plasticity. This pharmacological action is distinct from traditional antidepressants, which often require weeks to exert effects. Clinical studies have demonstrated ketamine’s potential to produce swift and significant improvements in mood, highlighting its therapy effectiveness in cases where conventional treatments fail. Administered via controlled intravenous infusions or nasal sprays, ketamine therapy is integrated within comprehensive mental health care plans, emphasizing patient monitoring and safety. Despite promising results, its use remains subject to ongoing research to fully elucidate long-term outcomes and optimal protocols. Thus, ketamine represents a critical alternative treatment, offering new avenues for patients unresponsive to existing therapeutic modalities.
What Is the Current Legal Status of Ketamine in Colorado?
Ketamine is listed in Schedule III under Colorado law and under federal regulations. Colorado places a drug in Schedule III when it has less potential for abuse than Schedule I and II drugs, has a currently accepted medical use in treatment in the United States, and its abuse may lead to moderate or low physical dependence or high psychological dependence, C.R.S. 18-18-205(1). That accepted medical use is why ketamine can be used in therapy at all. Who may give it, and when, is set by the general rules for controlled substances in part 3 of article 18.
Ketamine Legal Classification
Federal regulations list ketamine as a Schedule III depressant, 21 CFR 1308.13(c)(7). Colorado lists it in its own Schedule III, C.R.S. 18-18-205(2)(g). Schedule III status means ketamine may be prescribed and administered, but only by a licensed or registered practitioner.
Under Colorado’s prescription statute, the question is whether a practitioner dispensed or delivered the drug for medical treatment or authorized research in the ordinary course of the practitioner’s profession, C.R.S. 18-18-308(5). Possessing, sharing, or selling ketamine outside that framework is a crime, and the penalties are listed above.
Therapeutic Use Regulations
Colorado permits therapeutic use through its ordinary rules for controlled substances. The practitioner must hold a registration or license to dispense controlled substances, C.R.S. 18-18-302(1), and must keep records and inventories that meet federal record-keeping requirements and any rules adopted by the licensing board, C.R.S. 18-18-306.
A Schedule III drug that a patient takes home requires a written, oral, or electronic prescription. A practitioner other than a pharmacy may dispense it directly, C.R.S. 18-18-308(4).
Insurance coverage is a separate question. It depends on the patient’s plan and does not decide whether the treatment is legal.
Are There Specific Regulations for Ketamine-Assisted Therapy in Colorado?
Several Colorado statutes name ketamine specifically. They deal with its schedule, possession, distribution, and giving it to someone without their knowledge, C.R.S. 18-18-205, 18-18-403.5, 18-18-405, and 18-13-123. Ketamine therapy itself is governed by the general controlled substance rules described above and by the rules of each professional licensing board for the practitioners it licenses. This article does not cover those board rules.
Patient confidentiality is governed by general health privacy laws such as HIPAA.
How Do Medical Professionals in Colorado Navigate Ketamine Therapy Legality?
A practitioner who offers ketamine therapy works under the same controlled substance rules that apply to any other Schedule III drug. Those rules require the practitioner to:
- hold a registration or license that permits dispensing controlled substances, C.R.S. 18-18-302(1);
- dispense or deliver ketamine only for medical treatment or authorized research in the ordinary course of the practitioner’s profession, C.R.S. 18-18-308(5);
- keep records and inventories that meet federal record-keeping requirements and any board rules, C.R.S. 18-18-306; and
- follow the limits on Schedule III prescriptions, which cannot be filled or refilled more than six months after the date of the order or refilled more than five times, C.R.S. 18-18-308(4)(c).
Thorough informed consent and detailed medical records also help show that treatment was given for a medical purpose. Insurance coverage affects cost, not legality.
What Distinguishes Legal Ketamine Therapy From Illegal Use in Colorado?
The difference is authorization. Ketamine is legal when a practitioner dispenses or administers it for medical treatment, or when a patient holds ketamine that a practitioner prescribed or dispensed to them. It is illegal when a person possesses it without that authorization, shares or sells it, or gives it to someone without their knowledge. Insurance coverage plays no part in that test.
| Aspect | Legal Ketamine Therapy | Illegal Use |
|---|---|---|
| Who provides it | A practitioner licensed or registered to dispense controlled substances | Anyone without that authorization |
| Purpose | Medical treatment or authorized research in the ordinary course of the practitioner's profession | Any other purpose, including recreational use |
| How the patient gets it | Given directly by the practitioner, or by written, oral, or electronic prescription | Bought, shared, or obtained without a prescription |
| Possession | Lawful for the patient, in the container it was delivered in | Any amount is a level 4 drug felony |
Because possessing any amount of ketamine without authorization is a felony, the line between lawful therapy and a criminal charge is sharper for ketamine than for most other Schedule III drugs.
Are There Any Recent Legal Cases or Precedents Involving Ketamine Therapy in Colorado?
This article does not identify any published Colorado appellate decision about ketamine therapy. Medical malpractice claims and insurance disputes are civil matters, outside the criminal statutes discussed here.
What the General Assembly has done is write ketamine into several criminal statutes by name:
- Giving ketamine to someone without their knowledge is a class 3 felony. It is not a violation when ketamine is distributed or dispensed “for bona fide medical needs by or under the direction of a person licensed or authorized by law to prescribe, administer, or dispense such substances,” C.R.S. 18-13-123(4)(a), (5).
- The possession and distribution statutes single out ketamine for stricter treatment than other Schedule III drugs, C.R.S. 18-18-403.5(2)(a) and 18-18-405(2).
- “A peace officer shall not use, direct, or unduly influence the use of ketamine upon another person,” C.R.S. 18-8-805(1). An officer who is also certified as an emergency medical service provider may administer ketamine under separate restrictions, C.R.S. 18-8-805(2)(d).
How Does Ketamine Therapy Compare Legally to Other Controlled Substances in Colorado?
Ketamine is governed by the same statutes as opioids, benzodiazepines, and other controlled substances. It does not sit in a less regulated space. In one respect, Colorado treats it more strictly than its schedule would suggest.
Possessing any amount of most Schedule III, IV, or V drugs is a level 1 drug misdemeanor, and only a fourth or later offense becomes a level 4 drug felony. That rule excludes ketamine by name, so possessing any amount of ketamine is a level 4 drug felony from the first offense, C.R.S. 18-18-403.5(2)(a), (2)(c).
For distribution, the weight thresholds for ketamine are the same as those for methamphetamine and heroin: 7 grams and 112 grams, C.R.S. 18-18-405(2). For other Schedule III drugs, distributing more than four grams is a level 3 drug felony and four grams or less is a level 4 drug felony, C.R.S. 18-18-405(2)(c)(IV) and (2)(d)(I).
What Future Legal Developments Are Expected Regarding Ketamine Therapy in Colorado?
No one can say for certain how these laws will change. The General Assembly revisits them regularly. For example, C.R.S. 18-13-123 has been amended seven times since it was enacted in 1999.
The sections cited on this page are from the 2024 Colorado Revised Statutes. Check the current version of a statute before relying on any figure here, and speak with a lawyer about your own situation.
Frequently Asked Questions
What Are the Potential Side Effects of Ketamine Therapy?
Ketamine therapy’s potential side effects include dissociation, dizziness, nausea, increased blood pressure, and perceptual disturbances. Legal implications necessitate strict adherence to regulatory guidelines to ensure patient safety and ethical administration. Effective side effect management involves careful dosing, monitoring during sessions, and post-treatment observation to mitigate adverse reactions. Clinicians must balance therapeutic benefits with these risks, maintaining compliance with legal standards to uphold treatment legitimacy and patient well-being.
How Long Does a Typical Ketamine Therapy Session Last?
The length of a session and the number of sessions vary with the administration method and the clinic’s treatment protocol. Ask the treating practitioner what schedule they recommend. A structured approach lets the practitioner monitor the patient’s response and side effects and tailor the plan to the individual patient.
Can Ketamine Therapy Be Combined With Other Treatments?
Ketamine therapy can be combined with other treatments to enhance therapeutic outcomes, a practice known as therapy integration. This approach often involves pairing ketamine sessions with psychotherapy, cognitive behavioral therapy, or medication management. Combining treatments allows clinicians to address multiple aspects of a patient’s condition simultaneously, potentially improving efficacy and durability of results. Careful assessment and coordination are essential to optimize safety and therapeutic synergy during such integrative treatment plans.
Is Ketamine Therapy Covered by Insurance in Colorado?
Coverage depends on the individual insurance plan. Ask the insurer before starting treatment. Whether a plan pays for ketamine therapy does not affect whether the treatment is legal. Legality turns on whether a licensed practitioner dispensed or administered the ketamine for medical treatment, C.R.S. 18-18-308(5).
What Qualifications Should a Ketamine Therapist Have?
The person who prescribes, administers, or dispenses ketamine must be a practitioner licensed, registered, or otherwise permitted by the state to dispense or administer controlled substances, C.R.S. 18-18-102(29) and 18-18-302(1). A therapist who is not authorized to dispense controlled substances may still provide talk therapy alongside treatment given by an authorized practitioner. The statutes discussed on this page do not create a separate state ketamine certification, so ask any provider what license they hold and what training they have in ketamine treatment.