Promethazine: Everything You Need To Know


If you listen to hip-hop, chances are you’ve heard of Promethazine.

According to your favorite rapper, it’s the best!

But do you really know anything about it?

What it is?

What it does?

How it works?

If you’re like most people, the answer to those questions is a resounding NO!

Well, not to worry…

In this article, we’re going to cover everything you need to know about Promethazine, including:

  • What It Is
  • How It Works
  • Side Effects
  • Dosage Info
  • Recreational Use (That Lean)

And of course I’ll offer my personal opinion based on the research I’ve done and my personal experience.

So, if you want to know the facts about Promethazine, read on my friend…

What Is Promethazine?

What Is Promethazine?

Promethazine is a medication used to treat respiratory conditions (like asthma), symptoms of motion sickness (like nausea), and to enhance the efficacy of narcotic pain medications (like codeine).

Chemically, it looks like this:

Promethazine Molecule

It was originally developed way back in the 1940’s to treat symptoms of the common cold, coughs, and allergies, and is still used today for the very same reasons.

Typically, it comes in either tablet or liquid form.

The liquid form tends to have a thick, syrupy consistency, similar to OTC medications like Nyquil and Robitussin.

You’ll find Promethazine sold under the brand names:

  • Avomine
  • Phenergan
  • Progene

Unlike OTC products like Nyquil and Benadryl, you can’t just walk into a store and buy Promethazine though.  It requires a valid prescription from a licensed health care professional.

But we’ll talk more about the legal aspect of Promethazine later on.

First, let’s discuss how this stuff works in the first place…

How Does Promethazine Work?

How Does Promethazine Work?

Promethazine belongs to a unique class of chemicals called phenothiazines.

Although all phenothiazines are chemically related, their medicinal uses vary pretty widely.

Some of them are:

  • antihistamines
  • antipsychotics
  • anesthetics

Promethazine is primarily used as an antihistamine, but also has mild sedative properties as well.

Okay so…

What is an antihistamine?

Histamine is a chemical which plays a critical role in immune response.  It gets released by the body in response to foreign substances or pathogens and is responsible for certain symptoms of allergies.

So, an antihistamine is any substance that blocks the action of Histamine.

Such substances are useful for combating allergy symptoms.

For the most part, that’s what Promethazine is used for.

Like other “older antihistamines”, Promethazine does cause some level of sedation though.  It is believed to potentiate the effects opiods, such as Codeine.

To be honest, there isn’t much research comparing the impact of opiods and promethazine vs either of them alone, but logic would suggest that a sedative could amplify the effects of other sedatives.

Is it safe?

Well, that depends mostly on the dosage…

Promethazine Dosage

Promethazine Dosage

Promethazine comes in several dosages, depending on the form.

Promethazine tablets come in:

  • 12.5mg
  • 25mg
  • 50mg

Promethazine syrup, on the other hand, allows for much more flexible dosing.

It comes in various strengths, the most common of which are:

  • 25mg/ml
  • 25mg/5ml
  • 25mg/25ml

Since it’s a liquid though, you can literallly dose it however you want.

This makes it a little bit more dangerous than the pills and one of the reasons why Promethazine/Codeine syrup (also known as “Lean”) is so widely abused.

We’ll talk about that particular combination and it’s widespread recreational use as well, but Promethazine on its own does have some potential side effects you should be aware of first…

Promethazine Side Effects

Promethazine Side Effects

Newer antihistamines (like Benadryl) don’t carry the same risk of side effects as Promethazine, mostly due to its sedative properties.

Like any sedative, we’re talking about:

  • Drowsiness
  • Dizziness
  • Headache
  • Blurred vision
  • Slurred speach
  • Lack of coordination

Of course, there are also some more serious side effects as well…

In some cases (and at high enough doses), things like:

  • hallucinations
  • jaundice
  • respiratory depression

may occur.

These are rare, but become more likely when Promethazine is combined with other substances (which it often is).

Combining Promethazine With Other Drugs

Mixing Promethazine With Other Drugs

Promethazine can potentially interact with a wide range of other substances including:

  • Anti-anxiety Drugs
  • Pain Killers (Opiods)
    • Codeine
    • Oxycodone
    • Fentanyl
  • Muscle Relaxants
  • Sleep-Aids
    • Zolpidem (Ambien)
    • Eszopiclone (Lunesta)
  • Anti-Depressants
    • Zoloft
    • Welbutrin
  • Anti-Psychotics
    • Lithium
    • Haldol
  • Alcohol

Pretty much anything that’s psychoactive can potentially interact with it, sometimes in some pretty unpredictable ways.

So, you should DEFINITELY NOT combine it with other things without first consulting with your doctor.

Obviously, the most common substance that is combined with Promethazine is Codeine, an opiate that kills pain.

Promethazine And Codeine (AKA “That Lean”)

Promethazine And Codeine

Promethazine and Codeine is nothing new…

It’s a combination that has been used medicinally since the 1950’s, but in the last decade or so we’ve seen a massive increase in recreational use.

I’m not going to point any fingers here, but obviously this comeback has a lot to do with pop culture.

The combination of Promethazine and Codeine in the form of cough syrup was originally made popular by hip-hop artists, particularly in Houston, Texas.

Slang terms for this particular combination of substances in liquid form include:

  • Syrup (kind of an obvious one)
  • Sizzurp (an iteration of the first one)
  • Lean (because it sedates you)
  • Purple (because it’s often the colored purple)
  • That Good Drank (because they really like it I guess)
  • Potion (because it’s mixed with Sprite and possibly other things)

Obviously, there are plenty of slang terms for every drug, and Promethazine/Codeine is no exception.

These are just a few of the most common, but you can rest assured that as the popularity continues to spread, new street names will keep coming.

Hip-hop reaching the mainstream may have to do with the increase in popularity but it probably has more to do with the fact that Codeine is a super addictive narcotic.

Once you’re on it, you’re on it.

Suddenly stopping can cause terrible withdrawal symptoms, so if you’ve been sippin’ that lean continuously for a while, it’s really not a good idea to just stop.

Cough syrup may seem harmless, but this particular kind of cough syrup should be treated just as any other opiate or opiod and you should withdraw accordingly (a little bit at a time).

Is Promethazine Legal?

Is Promethazine Legal?

Promethazine is perfectly legal, but does require a valid prescription from an actual doctor.

By itself, it’s not considered particularly addictive or dangerous though, so it’s not even scheduled under federal law.

That mostly because it’s an “older antihistamine” though, not because it actually doesn’t have abuse potential.

It’s also just not as commonly prescribed as it once was since newer antihistamines (like Benadryl) have been introduced which still help with allergies and coughs, but aren’t as sedating.

When combined with Codeine, however, Promethazine is considered a Schedule V controlled substance.

Schedule V substances are those that have legitimate medical uses but aren’t as likely to be abused as schedule IV substance like benzos and some muscle relaxants.

As we’ve already discussed, it definitely IS abused though.

This also creates a bit of a legal gray area since Codeine itself is a Schedule II substance.  Ultimately though, it comes down to a matter of how much Codeine is present.

If it’s a high enough concentration, Prometh/Codeine could be considered Schedule II which of course carries a much higher penalty for possession and/or distribution than Schedule V.

Alternatives To Promethazine

Promethazine Alternatives

As an antihistamine–a treatment for allergies–there are certainly better alternatives to Promethazine:

  • Cetirizine (Zyrtec)
  • Diphenhydramine (Benadryl)
  • Fexofenadine (Allegra)
  • Loratadine (Claritin)

These are just a few of the main ones.  Some of them are more likely to cause drowsiness than others, but none of them hit as hard as Promethazine.

Because of that, these new allergy medications have become known as “new antihistamines”.

If you’re using Promethazine for its recreational potential though (to get high), you wouldn’t want to take those alternatives instead.

They won’t do the trick.

If it’s a sedative-like high you’re chasing, you need something like Alprazolam (Xanax) or Etizolam.

My Personal Opinion On Promethazine

My Opinion On Promethazine

I typically don’t like drugs that slow you down.  I have things to do.

Furthermore, Promethazine alone doesn’t provide the type of “high” that Promethazine/Codeine does.  It’s really the Codeine that causes that warm, high sensation.

That’s because it’s an opiate.

They all have similar effects, but Promethazine may amplify those effects to some degree.

I’m not a fan of opiates or opiods, even for the purposes of killing pain for two reasons:

  1. They’re incredibly addictive
  2. They slow you down

Obviously, opiates are useful for pain management, but I’ve never had any type of medical condition or severe injury that warranted the use of opiates so I can’t really comment on the risk/reward trade-off in those instances.

Since Promethazine has no inherent pain-killing properties though, and really just causes you to fall asleep, I don’t quite understand the recreational appeal.

I think a lot of people are just confused because rappers mention it here and there but don’t usually mention the fact that they’re combining it with Codeine.

If you want to get high, don’t drink Promethazine…

Smoke a joint.

The Bottom Line On Promethazine

The Bottom Line On Promethazine

By itself, Promethazine is an effective antihistamine, so it can help combat symptoms of allergies and will definitely put you to sleep.

That said, there are plenty of alternatives, even if you’re using it recreationally to get high or sleep better.

We’re talking about a drug that was invented 70 years ago and doesn’t really do anything on it’s own that can’t be accomplished with other substances.

Unfortunately, because it’s often combined with Codeine in the form of cough syrup, a lot of people are drinking Promethazine without realizing they’re actually using a powerful, highly addicted opiate as well.

So, whether you have a bad cough, a runny nose, or trouble sleeping, there are better alternatives to Promethazine.

Just because your favorite rapper mentioned it in a song doesn’t mean you should use it!

I’m Matt Theis, founder of SuppWithThat, Momentum Nutrition, and Singular Sport. I created SWT to separate the science from the hype and publish accurate, research-based information on supplements. If you like what I have to say here, feel free to check out my supplements at and

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