Key takeaways:
Controlled substances are drugs and medications with a risk of misuse and dependence. They’re regulated under the Controlled Substances Act (CSA), which is enforced by the DEA.
The CSA divides controlled substances into five schedules, with Schedule 1 carrying the highest risk and Schedule 5 the lowest. Each schedule has its own rules for prescribing and refilling, and some states have stricter laws than federal regulations.
Always follow your prescriber’s directions when taking controlled substances. Store them securely and stay alert for signs of misuse to help keep yourself and others safe.
Some medications carry more risks than others. Controlled substances are drugs and medications that carry a risk of misuse and dependence. They’re regulated by stricter laws around how these prescriptions are filled and monitored. Understanding how these rules work can help you avoid surprises at the pharmacy.
Here’s what to know about controlled substances, how they’re classified, and how these rules may affect your prescription.
What are controlled vs. noncontrolled substances?
All medications are regulated, but some are subject to stricter laws than others. Because of safety concerns, federal and state laws divide prescription medications into two main groups: controlled and noncontrolled.
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Noncontrolled substances
Most prescription medications fall into the noncontrolled category. These medications do not have a significant risk of misuse or dependence and are generally easier to prescribe and refill.
Some examples of noncontrolled medications include:
Antibiotics, such as amoxicillin and azithromycin (Zithromax)
Blood pressure medications, such as lisinopril (Zestril, Qbrelis) or clonidine (Catapres, Kapvay)
Diabetes medications, such as metformin (Riomet) and semaglutide (Ozempic, Rybelsus)
Asthma inhalers, such as albuterol (ProAir, Ventolin HFA) and Advair (fluticasone / salmeterol)
Antidepressants, such as escitalopram (Lexapro) and sertraline (Zoloft)
Antihistamines, such as hydroxyzine and loratidine (Claritin)
Antipsychotics, such as quetiapine (Seroquel) and olanzapine (Zyprexa)
In most cases, your prescriber can provide up to 1 year’s worth of refills on a prescription for noncontrolled substances. And while insurance plans may limit each fill to a 30- or 90-day supply, you could theoretically pay out of pocket for an entire year’s worth of medication if you wanted to. You can also typically refill a noncontrolled substance about 1 week before you run out of the previous fill.
Controlled substances
Controlled substances, on the other hand, are medications that carry a risk of misuse, dependence, and/or overdose. Because of these risks, stricter rules govern how these prescriptions are written, filled, and refilled. Controlled substances are regulated and classified based on how likely they are to cause dependence or be misused (more on that later).
Common examples of controlled substances include:
Stimulant ADHD medications, such as Adderall (amphetamine salt combo) and lisdexamfetamine (Vyvanse)
Benzodiazepines, such as alprazolam (Xanax) and clonazepam (Klonopin)
Opioid pain medications, such as methadone and oxycodone
Sleep medications, such as zolpidem (Ambien)
Illegal drugs, such as cocaine and heroin
In most cases, controlled substances are limited to five refills or less. And you won’t be able to refill a controlled substance until only 2 or 3 days before you run out of your previous fill. There are also limits on the quantity of a controlled substance you can purchase at a time — whether or not you use insurance.
Good to know: Some medications that aren’t controlled substances at a federal level are considered controlled substances by certain states. Gabapentin (Neurontin) is a common example. You’ll need to check the laws in your state to determine whether a medication is considered a controlled substance where you live.
How are controlled substances classified?
The Controlled Substances Act (CSA) is a federal law that regulates drugs and medications based on their risk of misuse and dependence. It’s enforced by the Drug Enforcement Administration (DEA).
The CSA groups drugs and medications into five categories, known as schedules, based on their risks. Each schedule has different rules about how and when prescriptions can be filled or refilled. Schedule 1 medications have the most restrictions, and Schedule 5 medications have the least.
The CSA determines schedules on a federal level. But states can make their own rules regarding controlled substances. However, in most cases, states can only increase the restrictions on a medication (i.e., lower the drug schedule). They cannot move a medication to a less-regulated schedule or reduce restrictions on it in most cases. For example, the federal law allows refills on prescriptions for benzodiazepines, but New York state does not. So it’s best to check the controlled substance laws in your state for the most accurate information regarding your prescription.
Let’s take a closer look at the five schedules and examples of medications they include.
Good to know: Controlled substances are categorized as Schedule 1, 2, 3, 4, or 5. You may see the schedule numbers written in Roman numerals or denoted by the letter C. For example, a Schedule 2 medication may be described as “Schedule II,” “C2” or “C-II.”
Schedule 1 controlled substances
According to the CSA, substances in Schedule 1 have no currently accepted medical use and a high potential for abuse. Schedule 1 drugs are not legally available for use, even with a prescription.
Examples of schedule 1 drugs include:
Heroin
Psilocybin
Mescaline (peyote)
LSD
Good to know: Cannabis is also considered a Schedule 1 drug at the federal level. But many states have legalized its use. The federal government is also considering rescheduling cannabis. So its status as a Schedule 1 drug is less clear than other members of this class.
Schedule 2 controlled substances
Schedule 2 controlled substances have FDA-approved medical uses. But they carry a high potential for misuse and severe psychological or physical dependence. The CSA places strict requirements on Schedule 2 prescriptions, and many states, pharmacies, and insurance plans also have their own rules or policies around them.
The most commonly prescribed Schedule 2 controlled substances are opioids for pain and stimulants for ADHD. Some examples include:
Methylphenidate (Ritalin)
Morphine
Methadone
Oxycodone
No refills are allowed on Schedule 2 prescriptions. This means you must get a new prescription each time you fill it. Some states require a hand-written prescription signed by your prescriber, but many now allow secure electronic prescriptions. Many states and insurance plans also limit you to a 30-day supply or less when filling a Schedule 2 controlled substance.
Schedule 3 controlled substances
Schedule 3 controlled substances have a lower potential for misuse than substances in Schedules 1 or 2. But they carry a high risk of psychological dependence and a low-to-medium risk of physical dependence.
Some examples of Schedule 3 medications are:
Suboxone (buprenorphine / naloxone)
Tylenol #3 (acetaminophen / codeine)
Fiorinal (butalbital / aspirin / caffeine)
You can refill Schedule 3 prescriptions in most states, but only up to five times or within 6 months from the date the prescription was written.
Schedule 4 controlled substances
Schedule 4 controlled substances have a lower potential for misuse and dependence compared with those in Schedule 3.
Examples of commonly prescribed Schedule 4 medications include:
Benzodiazepines, such as alprazolam and lorazepam (Ativan)
Sedatives for insomnia (“Z-drugs”), such as zolpidem and eszopiclone (Lunesta)
Carisoprodol (Soma)
Tramadol (Conzip)
Eluxadoline (Viberzi)
You can typically refill Schedule 4 controlled substance prescriptions up to 5 times within 6 months of the date they were issued. After that, you’ll need a new prescription.
Schedule 5 controlled substances
Schedule 5 controlled substances have a relatively low potential for misuse and dependence. Some examples are:
Pregabalin (Lyrica)
Robitussin AC (codeine / guaifenesin)
Lomotil (diphenoxylate / atropine)
There aren’t any federal restrictions on how many refills your prescriber can put on a Schedule 5 prescription. But some states may apply the same 5 refills/6 months limit as for drugs in Schedules 3 and 4.
What to know if you’re prescribed a controlled substance
If you’re prescribed a controlled substance, the following tips can help increase your safety and reduce the risk of misuse.
Understand your treatment plan. Talk with your prescriber about how often to take the medication and what kind of relief to expect. You should also ask about the treatment timeline. Some controlled substances are meant only for short-term use. For example, opioid pain medications can be helpful for severe, short-term (acute) pain but are usually not a first-choice option for chronic pain. Taking the lowest effective dose for the shortest possible time can help limit side effects and risks.
Don’t abruptly stop a controlled substance after taking it long term. Missing doses or abruptly stopping a controlled substance can lead to withdrawal symptoms — especially after long-term use. To prevent treatment gaps, get in touch with your pharmacist or prescriber for a refill or new prescription about 1 week before you are out of the medication. If you want to lower your dose or stop taking a controlled substance, contact your prescriber so they can guide you safely through the process of tapering off your medication if necessary.
Use one pharmacy for all of your medications. Filling all of your prescriptions at the same pharmacy helps pharmacists check for interactions, monitor safety, and avoid delays. There are often restrictions when it comes to how much of a medication a pharmacy can order for controlled substances, and how often. Using the same pharmacy each month helps ensure that they’ll be able to keep your regular medications in stock.
Store controlled substances securely. Keep all medications, especially controlled substances, up and away from children and pets. Depending on your living situation, you may want to lock up controlled substances where other people can’t get them. Expired or leftover medications, especially opioids, can be misused by others if not stored or disposed of properly. Ask your pharmacy about safe disposal options if you no longer need the medication.
Watch for signs of misuse. Controlled substances can increase the risk of substance use disorder, especially when taken longer than intended or at higher doses. Warning signs may include having strong cravings; running out of medication early; or encountering problems at work, school, or home. If you notice these changes, don’t wait to ask for help. Reach out to your healthcare team to discuss next steps and support options.
Know the overdose risks and how to reduce them. Taking more than one controlled substance raises your risk of substance misuse and overdose. For example, combining opioids with alcohol or benzodiazepines greatly increases the risk of overdose. If you take more than one controlled substance, talk to your healthcare team about separating your doses and other ways to take them safely. If you take an opioid, ask about keeping naloxone (Evzio, Narcan) on hand. It’s a medication that can reverse an opioid overdose in an emergency.
Never share your medication. Sharing prescription medications is illegal and can seriously harm others. For example, taking stimulants prescribed for ADHD without a prescription — such as for studying or staying awake — can raise the risk of side effects, including heart problems.
If you or someone you know struggles with substance use, help is available. Call SAMHSA’s National Helpline at 1-800-662-4357 to learn about resources in your area.
Frequently asked questions
The 28-day prescription rule for controlled substances refers to how soon you are allowed to get your next refill. When you fill a controlled substance prescription written for a 30-day supply, most pharmacies require that at least 28 days pass from your last fill date before they will dispense the next one. In practical terms, that means you can usually pick up your refill 1 or 2 days before your current supply runs out, but not sooner. If you try to refill it before the 28-day mark, you’ll likely get a rejection message from your pharmacy stating that it’s too soon to refill your prescription. These limits are typically set by state laws or pharmacy policies.
Sometimes. Federal law allows a pharmacy to fill a controlled substance prescription written by a licensed healthcare professional in another state. But state laws may not allow out-of-state prescriptions for controlled substances. Pharmacists must follow the state law if it’s stricter than the federal law. And even if it’s legally allowed, a pharmacist may choose not to fill an out-of-state prescription for a controlled substance — especially if they can’t access your prescription history or reach your prescriber to verify any necessary information. Your best bet is to communicate with your prescriber and pharmacist in advance to avoid running out of medication while you’re away from home.
No, alcohol is not a controlled substance because it’s not included in the federal Controlled Substances Act (CSA). Alcohol is regulated by the Alcohol and Tobacco Tax and Trade Bureau, not the DEA. However, alcohol has similar effects on the body to controlled substances. It’s a central nervous system depressant with a high risk of misuse and dependence. Because of its risks, alcohol is heavily regulated, and activities such as underage drinking or driving under the influence carry serious penalties.
The 28-day prescription rule for controlled substances refers to how soon you are allowed to get your next refill. When you fill a controlled substance prescription written for a 30-day supply, most pharmacies require that at least 28 days pass from your last fill date before they will dispense the next one. In practical terms, that means you can usually pick up your refill 1 or 2 days before your current supply runs out, but not sooner. If you try to refill it before the 28-day mark, you’ll likely get a rejection message from your pharmacy stating that it’s too soon to refill your prescription. These limits are typically set by state laws or pharmacy policies.
Sometimes. Federal law allows a pharmacy to fill a controlled substance prescription written by a licensed healthcare professional in another state. But state laws may not allow out-of-state prescriptions for controlled substances. Pharmacists must follow the state law if it’s stricter than the federal law. And even if it’s legally allowed, a pharmacist may choose not to fill an out-of-state prescription for a controlled substance — especially if they can’t access your prescription history or reach your prescriber to verify any necessary information. Your best bet is to communicate with your prescriber and pharmacist in advance to avoid running out of medication while you’re away from home.
No, alcohol is not a controlled substance because it’s not included in the federal Controlled Substances Act (CSA). Alcohol is regulated by the Alcohol and Tobacco Tax and Trade Bureau, not the DEA. However, alcohol has similar effects on the body to controlled substances. It’s a central nervous system depressant with a high risk of misuse and dependence. Because of its risks, alcohol is heavily regulated, and activities such as underage drinking or driving under the influence carry serious penalties.
The bottom line
Controlled substances are drugs and medications that carry a risk of misuse and dependence. They’re regulated by the Controlled Substances Act (CSA), which is enforced by the DEA. The CSA groups controlled substances into five classes, known as schedules. Schedule 1 substances are the riskiest, while Schedule 5 medications have the lowest risk of misuse.
Each controlled substance schedule has different rules when it comes to how medications are prescribed and refilled. And state controlled substance laws may be stricter than the federal law. Understanding controlled substance laws in your state can help set realistic expectations and reduce confusion at the pharmacy. Be sure to follow your prescriber’s instructions for taking controlled substances, store them safely, and watch for signs of misuse to help protect the safety of yourself and those around you.
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