How Long Does Ephedrine Last in the Body? Half-Life & Duration Of Effects

How long do the effects of ephedrine last and what is the duration of time that this stimulant remains detectable in your body?

Users typically report an onset of effects within 15 to 60 minutes and a duration of peak action between 2 – 4 hours followed by an offset period that can last several hours.

Although ephedrine is commonly reported to have an elimination half-life of 3-6 hours, there are various factors that determine its duration of effects in individual users.

Some people are more sensitive to ephedrine’s effects and feel this drug remain active in their body for a longer period of time. Other people may have a tolerance to stimulants in general and not experience as significant a physiological response.

Each person will metabolize ephedrine at a unique rate depending on factors including body weight, body composition, gender, diet, hydration, other medications used, current health state, and more.

Clearance of ephedrine can also be increased or decreased with use of other substances including diuretics. According to Erowid, lowering the pH of urine will decrease the elimination half-life of this substance.

This drug has a pKa of 9.6, which is a measure of the strength of an acid in solution. At a urinary pH of 6.3, the elimination half-life of ephedrine is 6 hours, but this is reduced to 3 hours if urinary pH is decreased to 5.

Ephedrine Overview

Ephedrine is an alkaloid compound extracted from the Ephedra sinica plant. It acts as a central nervous system stimulant and is sometimes prescribed as an antiasthma medication.

In the 1980s and 1990s, this fat-burning agent was included in numerous dietary supplements that were marketed for increasing energy, improving the mood, enhancing stamina, and losing weight.

However, in 2004, the US Food and Drug Administration banned ephedrine and its related alkaloids from being used in these products. [1]

Ephedrine and pseudoephedrine can still be included as ingredients in over-the-counter medications used for treating symptoms of bronchial asthma and other respiratory disorders.

The FDA banned ephedrine alkaloids in dietary supplements due to a high risk of adverse reactions. Any possible benefits it might have for weight loss need to be considered against the risk of severe adverse effects including stroke, seizure, and death.

You can still purchase ephedrine medications without a prescription in the United States. However, their sale is strictly regulated because this ingredient can be used to manufacture illicit drugs like methamphetamine (crystal meth).

Each state has unique regulations concerning the sale, purchase, use, and possession of non-prescription and prescription medicines that contain ephedrine or pseudoephedrine.

Ephedrine Half-Life

How long does ephedrine last in the body and how long does the average person feel its effects?

Ephedrine pharmacokinetics have been reported as follows:

• 85% bioavailability
• Metabolized in the liver
• 15-60 minute onset of action when taken orally
• 3-6-hour elimination half-life
• 2-4-hour duration of action when taken orally
• 22%-99% urinary excretion [3]

The elimination half-life of a substance is the amount of time it takes for its major activity to begin to diminish in the body

In most people, ephedrine’s elimination half-life is reported to be between 3-6 hours. The dosage, product formulation and method of administration also affect its half-life.

When taken in oral tablet form, ephedrine’s effects normally begin to be felt about 20 minutes after administration. However, some people say it can take up to an hour to begin noticing effects.

The over-the-counter drugs available in the US that contain ephedrine HCL or sulfate must, by law, also contain at least one other ingredient. Pure Ephedrine is not allowed to be sold for public use in the United States and most other countries.

Nasal decongestant medications available without a prescription usually contain an expectorant compound called guaifenesin.

It is included in products like Primatene, Bronkaid, and EPHED Plus in much higher amounts than ephedrine alkaloids are. This makes it much more difficult for illicit drug makers to extract the pure active chemical.

Bronkaid contains 25 milligrams of ephedrine sulfate and 400 mg guaifenesin. Comparatively, Primatene tablets contain 12.5 mg of ephedrine hydrochloride (HCL) and 200 mg of guaifenesin.

According to one source, ephedrine HCL is composed of 82% ephedrine by weight while ephedrine sulfate contains about 77%. These two forms can have different durations of effects inside the body. [4]

Further, an individual’s metabolism of ephedrine can be affected by various factors.

It is important to pay close attention to the amount of ephedrine that a product contains. Using too much of this stimulant alkaloid can cause serious side effects including cardiovascular damage and adrenal fatigue.

However, appropriate use of this drug under medical supervision does not typically cause serious adverse effects in healthy people.

Because dietary supplements containing this ingredient are no longer legal in the United States, some bodybuilders and dieters take these cough medicines off-label to help them lose weight.

This practice is strongly advised against due to the potential for negative reactions.

How Ephedrine Works

Ephedrine is used to make breathing easier in people affected by various respiratory conditions. It works as vasodilator that dilates blood vessels in the body while constricting blood vessels in nasal passages.

It helps to open respiratory passageways while alleviating inflammation and swelling in the nostrils that can cause feelings of congestion.

This stimulant works in part by mimicking the activity of a neurotransmitter and hormone called norepinephrine. It can stimulate alpha and beta-adrenergic receptors involved in regulating the Central Nervous System (CNS). [1]

Alpha, beta-1, and beta-2 adrenergic receptors are located in the blood vessels, the heart muscle, skeletal muscles, the lungs, and other parts of the body.

When ephedrine binds to these receptors, it initiates a Fight or Flight response like that which we experience in times of acute stress or physical danger. [1]

Some of the survival effects that make up the fight-or-flight response include:

• Increased blood pressure
• Increased heart rate
• Increased cardiac contractility
• Pupil dilation
• Increased oxygen intake
• Greater muscle tension
• Increased mental focus increase [4]

As a result of its stimulant mechanisms of action, ephedrine is known to promote short-term weight loss, mostly associated with decreased fat mass.

However, clinical studies on these effects have only lasted up to 6 months. There is not enough reliable evidence to rate the efficacy or safety of using this drug for with loss for periods longer than 6 months.

Ephedrine tablets are commonly reported to suppress the appetite and delay gastric emptying. Its effects are increased when taken with caffeine and aspirin in an ECA Stack.

Ephedrine And Drug Tests

Products that contain ephedrine alkaloids are considered stimulants and performance enhancing drugs (PEDs).

They have been banned on US military bases, and by the National Collegiate Athletic Association (NCAA), National Football League (NFL), International Olympic Committee (IOC), and the World Anti-Doping Agency (WADA).

Ephedrine differs from methamphetamine (crystal meth) only by the addition of a hydroxyl group (-OH). It can cause false positive results on drug screen assays used by athletic associations and probation departments to detect amphetamines.

If you are preparing for an athletic event and want to use ephedrine to enhance your performance, check with the governing association for your sport to determine whether this drug is banned for you.

If you are concerned about this medication causing a false positive on a laboratory test, discontinue using it at least one week prior to testing. This will allow enough time for it to be completely cleared from the body.

Safety Concerns

Ephedrine is not recommended for children under 12 years of age or for women who are pregnant, want to become pregnant, or are breastfeeding.

Appropriate oral use of this medication does not usually cause severe adverse effects in most people. However, some negative side effects are associated with use of this stimulant compound including:

• Heart palpitations or rapid heartbeat
• Blurred vision
• Dizziness
• Headache

Misuse or abuse of ephedrine-based drugs can cause serious adverse effects including arrhythmia, tachycardia, myocardial infarction (heart attack) ischemic stroke, a brain seizure, or death.

Nasal decongestant and antiasthma medications that contain this active ingredient can interact with numerous drugs, herbs, and dietary supplements. Some of these include other stimulants, MAOIs, antidepressants, and pharmaceutical agents that get metabolized in the liver.

If you use any prescription medicines, then it is best to speak with your doctor or pharmacist before beginning to use an ephedrine product.

How long ephedrine lasts in your body will depend on various factors and your results may be different than those reported above.

Do not use ephedrine as a substitute for a healthy diet or regular exercise if you are trying to lose weight. Using this drug improperly in any form can cause long-term damage to your body.

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