Phentermine (Adipex-P, Lomaira) is an FDA approved appetite suppressant with an amphetamine-like prescription medication used to suppress appetite. The weight loss happens when you spend more calories then consumed and Phentermine helps you curb your appetite resulting in decreased caloric intake. Remember that the body uses calories when you are resting and even sleeping. The relevant scientific names for the general types of weight loss pills that have been available since the late 1950s are Phentermine and Phentermine Hydrochloride. When administered according to a doctor's instructions, medical studies show that the medicine is safe and effective. 

The recommended starting dose for Phentermine is 15 mg daily and maximum dose of 37.5 mg taken once a day. Now FDA has approved Lomaira, a 8 mg Phentermine that can be taken 3 times a day. For some people the effective dose with consultation with their prescriber can be 15 mg or 1/2 a pill of 37.5md taken first thing in the morning and before 5 pm. Phentermine should never be taken after 5pm as it can effect your sleep.

Mechanism of Action

Phentermine activates the central nervous system and stimulates the release of certain neurotransmitters like dopamine, epinephrine (adrenaline), and norepinephrine (noradrenaline). As a result, the central nervous system induces a “fight or flight”-like reaction, which causes increased heart rate, sweating, lack of appetite, and extra energy

Common side effects of Phentermine include :

Increased heart rate

Tingling or prickling feeling in hands or feet

Dry mouth

Sleeplessness

Nervousness 

Constipation

Phentermine is not appropriate for all overweight and obese patients. There are many contraindications for phentermine use, including, but not limited to: history of cardiovascular disease, history of addiction, history of agitated states, or current/recent use of certain medications or supplements.