Phentermine vs Methylphenidate compared: (which is stronger?)

January 9, 2024 |

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Both phentermine and methylphenidate are drugs that stimulate the CNS (central nervous system), that’s why they’re called CNS stimulants.

But do they work the same way and are they used for the same conditions?

Phentermine is a prescription medication approved by the FDA (Food and Drug Administration) for obesity treatment, while methylphenidate is a prescription drug to treat ADHD (attention deficit hyperactivity disorder), ADD (attention deficit disorder), and narcolepsy (chronic sleep disorder that causes sudden attacks of sleep and overwhelming daytime drowsiness).

Methylphenidate is also FDA-approved.

Although they both stimulate the brain and central nervous system to create neurotransmitters, they work in different ways and are used for different conditions.

Still, is it possible to use phentermine for ADHD, ADD, and narcolepsy? How about methylphenidate – is it also good for obesity?

Continue reading to find out.

Phentermine Vs Methylphenidate – What Are They?


Phentermine formula

It’s an FDA-approved prescription drug used for managing obesity.

As a CNS (central nervous system) stimulant, it works by stimulating your brain to produce more neurotransmitters (e.g., norepinephrine, serotonin, and dopamine). The increased levels of neurotransmitters help make you feel fuller for a longer time, suppressing your appetite.

Higher levels of neurotransmitters also activate your body’s “fight or flight” response, giving an adrenaline rush that can motivate you to work out harder than you did before.

The bad news is that phentermine has the potential for abuse. Your doctor isn’t likely to prescribe this longer than 12 weeks, especially if you have experienced drug abuse in the past.

It can also cause various side effects, with some serious ones, such as worsening heart conditions or causing heart emergencies. We’ll discuss more of these side effects below.

Phentermine Forms & Dosage Options

Phentermine comes in different forms and dosages, including the following:

  • Lomaira (tablet): 8 mg
  • Suprenza and generic forms (capsule or oral disintegrating tablet): 15 mg, 30 mg, and 37.5 mg
  • Adipex-P (capsule or tablet): 37.5 milligrams (mg)

Possible Costs

Phentermine costs can vary, depending on different factors. As expected, generic drugs are cheaper or just around $16-23 per 30 tablets ($0.55 – $0.78 per unit), while brand names like Adipex-P can cost around $65-125 for 30 tablets ($2 – $4.20 per unit).

These figures can be lower with insurance, but many companies don’t cover obesity treatments. So, you might expect to pay for these weight-loss pills without insurance.



It’s an FDA-approved prescription drug used for treating ADHD, ADD, and narcolepsy.

Like phentermine, it’s a CNS stimulant that works by stimulating your brain to produce more neurotransmitters.

It triggers the production of more norepinephrine and dopamine, which can increase attention and decrease symptoms of hyperactivity or impulsiveness.

IMPORTANT WARNING: Methylphenidate has a black box warning. It’s considered to be the FDA’s most serious classification. Drugs with this warning can alert patients and doctors that their drug effects might be dangerous.

It has a higher risk of causing abuse and dependence than phentermine.

Although it’s a medication for ADHD, it can actually cause ADHD-like symptoms such as the following for those who don’t have the condition but were mistakenly diagnosed with it and given this medication:

  • Hyperactivity
  • Restlessness
  • Nervousness
  • High blood pressure
  • Increased inattentiveness
  • Anxiety
  • Paranoia

So, it’s very important to make sure that you actually have ADHD before taking this medication. Your doctor will need to make the necessary tests to check if you have this condition.

Methylphenidate Forms & Dosage Options

Methylphenidate has more dosage options and forms than phentermine.

Some of these are:

  • Chewable oral tablet
  • Oral immediate-release tablet
  • Extended-release oral tablet
  • Extended-release chewable oral tablet
  • Extended-release orally disintegrating tablet
  • Extended-release oral capsule
  • Oral suspension
  • Oral solution
  • Transdermal patch

Your doctor will determine how much dosage you’ll need, but 60 mg is the maximum dose per day.

Brand names can include:

  • Aptensio XR
  • Concerta
  • Cotempla XR-ODT
  • Metadate ER
  • Methylin
  • Methylin ER
  • QuilliChew ER
  • Quillivant XR
  • Ritalin
  • Ritalin LA
  • Ritalin-SR

Possible Costs

The prices can vary depending on the brand you pick, the dosage, and where you buy the item. As expected, generic methylphenidate versions come at cheaper rates than the brand names.

For example, 60 pcs of 10 mg generic methylphenidate tablets costs around $58.80 at CVS Pharmacy, while the same dosage and number of Ritalin cost around $79.20. These prices are subject to change without prior notice, and can also vary depending on your location.

Other drug versions can cost higher.

For example, the extended-release version costs around $58 for 20 pieces.

Take note that generic drugs might not be available in every dosage you need, so you might need a different dose or try a branded option.

Phentermine vs Methylphenidate Side Effects

Phentermine Side Effects

Common Side Effects

The most common phentermine side effects can include the following:

  • Bad or bitter taste in your mouth
  • Headache
  • Dizziness
  • Dry eyes
  • Dry mouth
  • Constipation or diarrhea
  • Feeling nervous
  • Trouble sleeping (insomnia)
  • Restlessness
  • Fatigue, tiredness, and reduced energy levels from overstimulation
  • Reduced interest in sex
  • Erectile dysfunction

Serious Side Effects

Watch out for the following signs of the serious side effects of phentermine:

  • Mood changes or swings (it can induce psychosis)
  • Signs of an allergic reaction: rash, hives, itching, and red or swollen skin with or without fever, wheezing, unusual hoarseness, trouble breathing or swallowing, tightness in your throat or chest, swelling of your tongue, face, lips, mouth, or throat
  • Signs of a heart-related emergency: dizziness, chest pain, fast or abnormal heartbeat, trouble breathing, shakiness, fatigue (a weakness that doesn’t go away), or swelling in your arms or legs
  • Signs of high blood pressure: migraine (a very bad headache), dizziness, change in eyesight (blurry), or passing out
  • Signs of low blood sugar: headache, dizziness, shaking, a fast heartbeat, sweating, confusion, hunger, and feeling sleepy or weak

Phentermine can increase your risk of developing depression, anxiety, and other mood disorders.

If you’re pregnant or trying to conceive, talk to your doctor about taking phentermine because it can lead to the following serious side effects for pregnant women:

  • Increased risk of miscarriage
  • Increased risk of birth defects
  • Gestational diabetes
  • Pulmonary hypertension (a fatal lung disorder)
  • Preeclampsia (high blood pressure with organ failure)

Don’t use phentermine longer than what your doctor prescribed, and don’t double or change the dosage. This drug has the potential for abuse.

If you miss a dose, don’t double the dose when you remember.

Methylphenidate Side Effects

Common Methylphenidate Side Effects

Methylphenidate doesn’t cause drowsiness. However, it can have other side effects, including serious ones.

Here are some of the common side effects:

  • Decreased appetite
  • Headache
  • Nervousness
  • Nausea
  • Trouble sleeping
  • Upset stomach

Methylphenidate Serious Side Effects

Very important: Methylphenidate can cause serious side effects.

Consider the following before taking methylphenidate, and make sure to tell your doctor about any underlying medical condition you might have:

  • Allergic reactions – Like most drugs, methylphenidate can also cause an allergic reaction. Signs can include rashes, swelling of your face or throat, breathing troubles, and itching on some body parts, particularly the nose, neck, face, and lips.
  • Digestive problems warning – Some forms of methylphenidate, particularly Concerta, might be difficult to swallow and can cause a blockage of your esophagus, stomach, and/or intestines. However, you shouldn’t cut or break apart Concerta tablets (designed for extended release) because that might quickly increase the amount of medication in your body, increasing your risk of serious side effects.
  • Psychiatric disorders warning – This drug can cause psychotic or manic symptoms even in those who don’t have a history of mental health problems and can worsen the symptoms of those who do have one. Symptoms can include paranoia (feeling extremely suspicious) and hallucinations (hearing, seeing, or believing things that aren’t real).
  • Heart problem warning – Anyone with serious heart problems should avoid taking this drug because it can cause increased heart rate and blood pressure which can lead to a heart attack, stroke, or even sudden death.

Be sure to tell your doctor if you have an abnormal heart rate, high blood pressure, a history of heart attack, or heart failure. This drug might not be safe for you.

Phentermine Vs Methylphenidate Core Differences

Phentermine and methylphenidate are both approved by the FDA as drugs for varied purposes. Here are their core differences:

  • Both are prescription drugs that come in tablet form, but methylphenidate is also available as a transdermal patch.
  • Methylphenidate has more options in terms of dosage and brand names.
  • Phentermine is not covered by insurance, but most methylphenidate options are, especially generic. However, you can also find pharmacy coupons and discounted online options for lower prices. Note that you might be required a copay for the medications, which can vary. For some, cash payment (with special pharmacy discounts) might be cheaper.
  • Phentermine isn’t recommended for anyone below 16 years old. In contrast, methylphenidate can be taken by kids 4 years old and above, though it’s not suitable for all. Never give your child this medication unless it is prescribed by their doctor.
  • Both are controlled drugs that have the potential for abuse. However, methylphenidate has a black box warning, making it more dangerous than phentermine.

Can You Combine Phentermine & Methylphenidate?

Although phentermine and methylphenidate don’t interact with each other, it’s not advisable to combine these two.

Each drug is already dangerous on its own, with the possibility of addiction and serious side effects. If used in combination, they could amplify each other’s effects, leading to more dangerous situations.

Don’t ever combine these two medications, unless your doctor determines that the combination is the only course of action necessary for your condition.

Also read: Phentermine vs Adderall: What’s better?

Which Is Better? Phentermine Vs Methylphenidate



Usage: Obesity (short-term treatment of around 12 weeks) ADHD, ADD, and narcolepsy
Dosage form: Pill (oral) Pill (oral) and transdermal patches
Price: Around $16-23 per 30 tablets for 37.5 mg generic phentermine tablets Around $58.80 per 60 pcs for 10 mg generic methylphenidate tablets
Pros (upsides):
  • It can only help lose an average of 5% in body weight.
  • As high as 75% of users can lose at least 5% of their body weight.
  • It can help manage the symptoms of ADHD, ADD, and narcolepsy
  • It can increase focus and decrease the symptoms of hyperactivity or impulsiveness
  • It’s covered by insurance
  • It’s approved for use by children as young as 4 years old and above
Cons (downsides):
  • It can be addictive.
  • As a potentially habit-forming drug, it isn’t recommended for long-term use or longer than 12 weeks.
  • It isn’t recommended for anyone below 16 years old.
  • It’s usually not covered by insurance.
  • It can be addictive.
  • It’s a dangerous drug with a black box warning, a most serious classification given only to drugs that have the highest potential for very serious side effects.
Common side effects:
  • Bad or bitter taste in your mouth
  • Headache
  • Dizziness
  • Dry eyes
  • Dry mouth
  • Constipation or diarrhea
  • Feeling nervous
  • Trouble sleeping (insomnia)
  • Restlessness
  • Fatigue, tiredness, and reduced energy levels from overstimulation
  • Reduced interest in sex
  • Erectile dysfunction
  • Decreased appetite
  • Headache
  • Nervousness
  • Nausea
  • Trouble sleeping
  • Upset stomach
Potential side effects in children or teens (12-17 years old):
  • Not approved for use by this age group
  • It can cause psychotic or manic symptoms such as paranoia (feeling extremely suspicious) and hallucinations (hearing, seeing, or believing things that aren’t real), especially in children, and even for those who don’t have a history of mental health problems.
Potential side effects in pregnant women:
  • Increased risk of miscarriage
  • Increased risk of birth defects
  • Gestational diabetes
  • Pulmonary hypertension (a fatal lung disorder)
  • Preeclampsia (high blood pressure with organ failure)
  • It has a small but serious risk of causing major malformations, particularly congenital heart conditions if your baby is exposed to this drug during early pregnancy.
Serious side effects:
  • Potential for abuse and tolerance
  • Mood changes
  • Severe allergic reaction
  • Heart-related emergency or worsened heart disease
  • High blood pressure
  • Low blood sugar
  • Serious allergic reactions
  • Digestive problems (possible blockage of your esophagus, stomach, and/or intestines)
  • Mood changes and psychiatric disorders
  • Heart rate and blood pressure problems can lead to a heart attack, stroke, or even sudden death
  • Although an ADHD drug, it can actually cause ADHD-like symptoms to those misdiagnosed with ADHD and given this drug as treatment.

As you can see above, these two drugs are both FDA-approved CNS stimulants. Phentermine can be used for off-label treatment of ADHD (depending on your doctor), and methylphenidate might be used for obesity (because appetite suppression is one of its side effects).

But their major similarities stop there.

Phentermine is best suited for treating obesity through appetite suppression, while methylphenidate is used for ADHD, ADD, and narcolepsy.

Both have serious risks and potential for abuse. However, methylphenidate is worse because its risks are more dangerous, and it can even lead to stroke or death.

Of these two, phentermine might be slightly better.

However, we don’t recommend using these two because of their potential for very serious side effects. If you’re searching for something to help with obesity, we recommend PhenQ instead.

What’s a Better Alternative To Phentermine & Methylphenidate

PhenQ is a natural weight management system that stops cravings and helps you shed off excess fat. Aside from this dual-action, it also supports natural energy, giving you a power boost for working out.

The combination of these three actions can help you manage your weight loss and reach your goals faster.

What’s great about PhenQ is that, unlike phentermine and methylphenidate, it doesn’t have serious side effects, the potential for abuse, or dangerous risks (for long-term use).

That means that you can use PhenQ for as long as you want, giving you a better chance to lose weight and maintain it.

Plus, instead of causing mood disorders or increasing their symptoms, PhenQ can help balance your mood and reduce daily mental fatigue.


Is Phentermine Like ADHD Medication?

Although phentermine is primarily used as an obesity medication, it is also known for its off-label use for ADHD.

However, due to its potential side effects and reduced efficacy as ADHD medication, it might be the last option that your doctor might consider.

Can You Use Methylphenidate For Weight Loss?

Although primarily used as a drug to treat ADHD, ADD, and narcolepsy, methylphenidate might also be used for weight loss because appetite suppression is one of its side effects.

However, there are lots of medications and specialized anti-obesity drugs such as PhenQ that can be effective but without side effects. You might consider PhenQ instead of using methylphenidate, which can actually be deadly.

Is Duromine Similar To Ritalin?

Duromine is a brand of phentermine drug, while Ritalin is a brand of methylphenidate drug.

When Should You Take Phentermine?

Take only as directed by your doctor. It’s usually taken 1 hour before or 1-2 hours after breakfast.

Some formulations are taken twice a day, but make sure that the last dose is taken some hours before bedtime because phentermine can cause insomnia.

What Does Phentermine Feel Like?

As a stimulant, drinking phentermine can make you feel “high” and full so that you don’t feel hungry for a longer time.

This drug also produces neurotransmitters, brain chemicals involved in your body’s “fight or flight” response. So, you might notice an “adrenaline” rush after taking phentermine.

With this higher energy, you can have new motivation to work out.

How Quickly Does Phentermine Take To Work?

The full effects of phentermine, particularly appetite suppression and increased energy, are felt around 3-4.5 hours of taking the drug.

How Many Hours Does Phentermine Last?

It’s a long-acting medication that can last for up to 6-8 hours, possibly even longer. It would take at least 24 hours before it’s completely eliminated from your body.

When Should You Take Methylphenidate?

Always take methylphenidate as your doctor prescribed. This drug is usually taken 2-3 times a day, around 30-45 minutes before a meal.

What Does Methylphenidate Feel Like?

Like phentermine, methylphenidate can also make you feel “high” and energized. You might feel an “adrenaline rush” and huge motivation to work out.

It can stop you from feeling hungry, but also make you feel agitated or even aggressive.

How Quickly Does Methylphenidate Take To Work?

It’s a fast-acting drug (immediate-release form) that can work within 30-60 minutes.

The sustained-release form takes around 1-2 hours before you can feel the effects.

How Many Hours Does Methylphenidate Last?

Methylphenidate has a very short half-life of 1-4 hours, depending on the form.

That means that in around 1-4 hours, a 10-mg dose is reduced to 5 mg in your body. Another 1-4 hours later, it’s reduced to 2.5 mg, and so on.

Most people will completely eliminate methylphenidate from their bodies in 24 hours.


Phentermine is a prescription weight-loss drug that is used to help people lose weight. It works by suppressing the appetite and increasing the metabolism.

While on the other hand, Methylphenidate is a prescription ADHD medication that comes in pill form. It helps people focus and stay on task. Methylphenidate also has some dangerous side effects, but it is not addictive like phentermine.

Both are stimulants, so they work in similar ways.

We hope with the information and facts we’ve provided in this post – you’d be able to make an informed decision on which to go for and when.

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