What Is a Controlled Substance?

Drug categorization can be a confusing topic. It can also have a big impact on how you’re able to get the medicine you need. This is especially true if your healthcare provider prescribed a controlled substance. Besides federal restrictions, there are state regulations to consider.

In this article, we’ll talk about controlled substances. Learn what they are, how they’re classified, and what to know if you’re prescribed a controlled medication.

What are controlled vs. non-controlled substances?

We can break prescription medications into two sub-categories: controlled and non-controlled.

Most prescriptions for infections or for chronic conditions are non-controlled. For example, most blood pressure and cholesterol medications are non-controlled medications. Same with diabetes medications (including insulin), asthma inhalers, and antibiotics.

Controlled substances are medications that can cause physical and mental dependence. There are restrictions on how they can be filled and refilled. Controlled substances are regulated and classified by the DEA (Drug Enforcement Administration). Regulations are based on how likely they are for abuse and to cause dependence.

Some examples of controlled substances include:

• ADHD medications — like Adderall (amphetamine salt combo) and Vyvanse (lisdexamfetamine)

• Anti-anxiety medications — like alprazolam (Xanax) and clonazepam (Klonopin)

• Cannabis and marijuana products

• Nerve pain medications — like pregabalin (Lyrica)

• Opioid pain medications — like Norco (hydrocodone/acetaminophen) and tramadol (Ultram)

• Sleep medications — like zolpidem (Ambien)

Additionally, some medications aren’t considered controlled substances by the DEA. But they’re categorized that way in certain states. Examples include gabapentin (Neurontin) and pseudoephedrine (Sudafed).

How are controlled substances classified?

Controlled substances fall into different categories. These have different restrictions on how and when they can be filled or refilled. It’s important to know there can be more restrictions. Factors include your state, pharmacy, and insurance plan.

Schedule V controlled substances

Substances in this schedule have a lower potential for abuse versus those in Schedule IV. They consist primarily of preparations containing limited quantities of certain narcotics.

Schedule V medications may be refilled if your healthcare provider has given authorization. But, some states may restrict how many times you can get a refill.

One example of this type of drug is Robitussin AC. Other cough medicines with codeine are also in this category.

Schedule IV controlled substances

Let's compare to Schedule III medications. Schedule IV listed  medications have lower potential for abuse and dependence. You can get refills on Schedule IV medications. But only if your healthcare provider has authorized it on the prescription.

Each prescription may only be refilled up to five times within 6 months after the issuing date. After five refills or after 6 months, a new prescription is required. Common Schedule IV medications include benzodiazepine anxiety medications like Xanax or Klonopin.

Schedule III controlled substances

These medications have a lower potential for abuse than substances in Schedules I or II. But abuse may lead to moderate or low physical dependence. There is also potential for high psychological dependence. The refill process for Schedule III is the same as for Schedule IV and V. You may refill up to five times within 6 months.

One example is Suboxone (buprenorphine/naloxone), used to treat opioid dependence. Another is Tylenol with codeine for pain.

Schedule II controlled substances

These medications have a high potential for abuse. This can lead to severe psychological or physical dependence. There are special restrictions for filling and refilling Schedule II prescriptions.

Some states need a hand-written prescription signed by your healthcare provider. There are also no refills allowed on Schedule II prescriptions. This means you must get a new prescription each time from your healthcare provider.

Many states also limit the amount you are allowed to fill at one time to a 30-day supply. Opioid pain medications (like Vicodin or Percocet) are Schedule II. So are ADHD medications (like Adderall).

Schedule I controlled substances

Per the DEA, any substances in Schedule I have no currently accepted medical use in the United States. They have a high potential for abuse and are not available for use even with a prescription. An example would be heroin.

What to know if you’re prescribed a controlled substance

If you’re prescribed a controlled substance, the following are some things to keep in mind.

1. Discuss with your healthcare provider about directions, length of therapy, and expectations. Knowing more about how to take these controlled medications is helpful. This may lead to realistic symptom relief and limited side effects. For example, anti-anxiety medications — like clonazepam — can be effective short-term treatment options. To limit the risk of side effects and dependence, long-term use is not recommended. Typically these medications are used for short-term in combination with long-term first-choice options. It can take a few weeks to work.

2. If you’re going to be taking a controlled substance for a long period of time, don’t abruptly stop it. Suddenly discontinuing a long-term controlled medication can lead to severe withdrawal symptoms. To prevent treatment gaps, get in touch with your pharmacist or healthcare provider. You'll want to get a new prescription a few weeks before you are out of refills.

3. Use one pharmacy for all your medications. If you regularly use one pharmacy the pharmacy will try their best to keep your medications in stock. If you don’t, then the pharmacies may not always have your medications available. In fact, the pharmacy might have trouble ordering controlled medications for you. This is because their wholesalers will “flag” them for unusual purchasing amounts.

4. Talk to your provider if you’re experiencing symptoms of substance use disorder (SUD). Compared to other medications, controlled substances have a higher likelihood of causing SUD. Reach out to your healthcare provider if you’re having SUD-like symptoms. Symptoms include medication overuse and relationship troubles.  Low performance at home, school, or work may also occur. If you’re taking opioid pain medications, you have options. Your healthcare provider can prescribe naloxone (Evzio, Narcan) for you. You can also find it behind the pharmacy counter. Naloxone reverses the effects of opioids in the event of an overdose.

Why trust our experts?

Written by:

Ross Phan, PharmD, BCACP, BCGP, BCPS

Ross Phan is a board-certified clinical pharmacist. She has roughly two decades of healthcare experience — with most of her experience being pharmacy related.

Reviewed by:

Alyssa Billingsley, PharmD

Alyssa Billingsley, PharmD, is the director of pharmacy content for GoodRx. She has over a decade of experience as a pharmacist and has worked in clinical, academic, and administrative roles.

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