How long does it take for Adipex to kick in? (+ 3 factors)

In this article, we will explore how long it takes for Adipex to kick in, the factors that may influence the time period and what to do if Adipex does not kick in within the mentioned time.

How long does it take for Adipex to kick in?

Adipex (Phentermine) takes about 3-4.4 hours to kick in (1) but it takes weeks for it to work as a weight-loss agent (2). The effects of Adipex last for about 4-6 hours.

Adipex is a prescription weight loss medication that works by suppressing appetite and increasing energy expenditure (3). It is typically taken in the morning and it takes about 3-4 hours for it to reach its peak concentration in the bloodstream.  For most individuals, Adipex typically starts to take effect within a relatively short time frame after ingestion.

Users may notice reduced appetite, increased energy or a feeling of a bit more alert shortly after taking the medication (4). However, the full effects of Adipex in terms of appetite suppression may take a few days to become more pronounced as the body adjusts to the medication.  

The duration of effects of Adipex may vary from patient to patient but typically the effects last for 4-6 hours means the patient has to take Adipex twice a day to maintain its effects throughout the day. 

It is important to note that Adipex is not a magic bullet for weight loss. It is more effective when used in conjunction with a healthy diet and exercise regimen. 

What factors may influence the onset of action of Adipex?

Several factors may be held responsible for the effects of Adipex to be shown in the body. These factors include:

Metabolism

Variations in metabolism can significantly impact how quickly the body responds and processes Adipex. Individuals with faster metabolism may experience the effects sooner than those with a slower metabolism. 

Dosage and formulation

The dosage strength and the formulation of Adipex can affect the onset of action. Extended-release formulations might take longer to start working as compared to immediate-release versions (5).

Individual physiology

Each person’s body composition including weight, height, body fat percentage and overall health can influence how drugs like Adipex are absorbed and utilized in the body.

Empty stomach v/s full stomach

Taking Adipex on an empty stomach might lead to quicker absorption as compared to taking it with food may affect the onset of action of Adipex. However,  this has its own side effects. 

Drug interaction

Concurrent use of other medications or substances such as MAOIs, weight loss medications, serotonin modulators, antihypertensives, stimulants, antihistamines and alcohol can affect how quickly Adipex starts working. Interaction with other drugs might enhance or inhibit the absorption of Adipex resulting in modulation of its onset of action (6).  

Tolerance

Individual tolerance and sensitivity to medication may vary. Some individuals may be more sensitive to its effects experiencing its effects sooner while others might take a longer time. 

Overall health condition

Individuals with health conditions involving liver issues, and kidney issues could potentially influence the metabolism of Adipex resulting in a modulated time of onset (7).  

Compliance with the dosage schedule

Adherence to the prescribed dosage schedule can affect how consistently the drug goes into the system, potentially influencing its onset of action. 

It is crucial to note that factors may vary from person to person and the precise time of onset of Adipex can differ in individuals based on these factors. 

What to do if Adipex does not work?

If you have taken Adipex and have not experienced the onset of its actions in 3-4.4 hours, here are some steps you can consider:

• You might need to wait a little longer. While the typical onset time is of few hours, it might take a little longer in some individuals due to some factors.

• Double-check to confirm if you have taken the correct dose as prescribed by your healthcare provider. Ensure that you have followed the administration instructions.

• Do not take an additional dose without consulting your healthcare provider first. This can increase the risk of side effects.

• Consider if there might be interactions with other medications that may have slowed the time of onset. 

• If Adipex doesn’t show the expected effect even after the expected time frame, then it is advisable to consult your healthcare provider. 

Your healthcare provider might have to reassess your treatment plan. They might consider adjusting the dosage altering the time of administration and double-check your past medical record to determine any interactions that may possibly be a reason. 

Alternative medications

If you are taking Adipex and it is not showing its effects despite all the modifications in the treatment plan, then your doctor might have to explore other treatment options for you. The alternative medications that can be used for the same purpose as Adipex include:

• Orlistat
• Liraglutide
• Bupropion/naltrexone

Some non-prescription supplements can be helpful as well. These may include:

• Green tea extract
• Glucomannan
• Conjugated linoleic acid

Lifestyle and dietary modifications may be essential.

What are the potential side effects of Adipex?

Adipex like other medications has its own significant list of side effects. Some of these effects may be more commonly reported than others. Not every individual might feel these side effects due to individual sensitivity. The list of potential side effects includes (8):

• Insomnia or restlessness
• Dry mouth
• Increased heart rate
• Increased blood pressure
• Dizziness or headache 
• Nervousness or irritability
• Gastrointestinal issues
• Changes in libido or impotence
• Tolerance and dependency
• Allergic reactions
• Cardiovascular effects

It is essential to take Adipex under the careful supervision and regular monitoring of a  professional, experienced healthcare provider. Adipex is usually prescribed for short-term use as a comprehensive treatment program for weight loss (4). It is not usually prescribed for the long term due to its potential side effects.

In my perspective, Adipex has shown a specific time of onset in the research studies. The time recorded is 3-4.4 hours. However, if you don’t experience its effects within this time frame, it is better to consult your doctor so they can re-evaluate the treatment plan and determine the underlying cause of the delayed onset of Adipex in your body. 

References