Phentermine for Weight Loss: What You Need to Know
Phentermine is a commonly used medication for weight loss around the world, although it's not available in Canada. This article sheds light on what you should know before taking it, based on experiences of patients who have used it.
What is Phentermine?
Phentermine has many brand names, including Adepex, Duramine, Fastin, and Lomaira. It is an amphetamine-like stimulant that suppresses appetite. It was approved for weight loss in 1959 and has a long history of use. Because it has become generic, it is also relatively inexpensive, contributing to its global popularity.
How it Works
Phentermine works as an amphetamine-like appetite suppressant, stimulating the sympathetic nervous system (fight or flight). This activation shuts down unnecessary systems like the digestive system, leading to appetite suppression. The stimulant effects also help you feel more awake, encouraging physical activity and fat burning.
Side Effects and Risks
Phentermine has several stimulant-related side effects:
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Headaches
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Dizziness
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Tingling in hands and feet
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Heart palpitations
Regular screening of heart rate and blood pressure is crucial to prevent cardiovascular issues. People with a history of strokes or existing cardiovascular problems may not be suitable candidates. Phentermine can also worsen anxiety, so individuals with anxiety or mood disorders should consult their doctor.
Other Common Side Effects
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Insomnia (taking Phentermine earlier in the day may help)
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Gastrointestinal issues (nausea, constipation, stomach pain)
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Altered taste or dry mouth
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Drug interactions (especially with other stimulants or mood medications)
Addiction Potential
Phentermine is considered an amphetamine-like stimulant, and amphetamines can be addictive. While Phentermine might be less addictive than other amphetamines like Adderall, there is still a risk.
Experiences with Addiction
Some people do become addicted, relating it to the energy and positive feelings while on the drug, as well as the fear of weight regain. Discontinuing Phentermine can result in:
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Headaches
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Fatigue
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Weight rebound
These withdrawal symptoms are especially prevalent in patients who have taken Phentermine for longer periods at higher doses.
Interactions with Alcohol and Caffeine
Alcohol
Combining Phentermine and alcohol is not recommended. Alcohol can worsen negative side effects, especially for those with cardiovascular issues. It can also increase the addictiveness of both substances. Because Phentermine is a stimulant and alcohol is a depressant, combining them can lead to needing larger doses of both to achieve the same effects.
Caffeine
It's generally recommended to avoid other stimulants, including caffeine, while taking Phentermine. Adding more stimulation could worsen side effects like:
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Anxiety
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Restlessness
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Insomnia
A normal coffee or espresso per day is unlikely to cause issues for most people, but excessive caffeine intake should be avoided.
Effectiveness and What to Expect
Phentermine is most effective for short-term weight loss. Many people experience 5-10% weight loss in the first few months. However, this weight loss is frequently not sustained.
Limitations
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Phentermine can stop working after a few weeks, leading to plateaus or weight rebound.
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Extreme dieting while on Phentermine can increase the risk of weight rebound later.
The effects on appetite and weight are strongest initially and weaken over time. Increasing the dose only delays the inevitable and increases the risk of addiction.
Recommendations
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Use Phentermine as a temporary support tool for short periods.
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Develop a proper weight loss diet and transition to it as soon as possible.
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Consider using it as needed, such as a small maintenance dose during vacations.
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If you are not losing weight on Phentermine, taking a higher dose is unlikely to help.
Some people take Phentermine for years, even if it's no longer effective. A proper weight loss diet is essential to avoid rebound weight gain.