According to the media phentermine is America’s diet drug of choice. But is it safe? And what are the alternatives if you don’t want to take a pharmaceutical approach to losing weight? Let’s find out.
What is phentermine?
Phentermine is an amphetamine-like prescription medication used to suppress appetite. It comes as an oral capsule, tablet, and a disintegrating tablet.
It acts as a short-term weight loss (a few weeks) treatment for very overweight or obese people with certain health risk factors, including high blood pressure, raised cholesterol and diabetes.
Phentermine is intended for use as part of an overall weight-loss plan such as exercise, behavioural change, and calorie reduction belonging to a class of drugs called anorectics also known as appetite suppressants.
Phentermine works by increasing the release of three chemicals from nerve terminals in your brain, which helps to reduce appetite: norepinephrine, serotonin, and dopamine. When the levels of these chemicals increase, the feeling of hunger decreases, helping you to eat less and therefore, over-time, to lose weight.
It is possible to build a tolerance to the weight loss effects of phentermine within a month or so. If this occurs, the product’s use should stop. Phentermine is FDA approved for short-term use only, as there are no long-term studies on its safety. However, the FDA has approved phentermine (at a lower dose) combined with topiramate for long-term use.
Key brands: Adipex-P, Lomaira, Fastin, Suprenza
OTC phentermine – Where can I buy it?
Like similar prescription medications, phentermine, is not generally available over the counter. To buy this product you likely need to receive a prescription from a doctor and collect it at the pharmacy.
If you don’t want purchase phentermine from a store then there are alternative methods of getting it.
Brands such as Adipex-p, Lonamin and pro fast are often available from CVS, Honeybeehealth, Rite aid and other online pharmacies, making the process somewhat more convenient, though you will still need a medical prescription to purchase them.
Phentermine is not available at retailers like GNC or Walmart, but it is available at Walgreens.
Is phentermine safe? Side effects explained…
When choosing prescription medication such as phentermine, there will inevitably be certain side effects. Reported side effects of Phentermine include:
- heart palpitations
- loss of libido
Although further research is needed, some studies have reported that phentermine and similar products may increase the risk of hypertension in humans.
A further study referenced a female who experienced pulmonary arterial hypertension after five weeks of taking phentermine and suggested that further research is needed to establish the safety and recommended dosage level of the product.
Phentermine can be taken alone or used in combination with other medications for promoting weight loss. Fen-phen was a popular combination of phentermine and fenfluramine or phentermine and dexfenfluramine.
However, both fenfluramine and dexfenfluramine were removed from the market in 1997, when it was revealed that they may cause serious heart and lung problems. It is not clear whether phentermine alone may cause similar problems.
Phentermine should not be taken if you have heart disease, hyperthyroidism, glaucoma, or if you are pregnant or nursing. Your doctor will determine whether the product is appropriate and safe for you.
Best phentermine alternatives – Pharmaceutical options
Orlistat is a weight-loss agent with a novel mechanism of action and acts as a treatment option for obese people who want to lose weight.
It works by inhibiting gastric and pancreatic lipases in the lumen of the gastrointestinal tract to reduce systemic absorption of dietary fat. Treatment with orlistat may also offer small improvements in total cholesterol, LDL, blood pressure and fasting glucose.
Importantly, orlistat may reduce the absorption of fat-soluble vitamins, taking a multi-vitamin during orlistat therapy is recommended to prevent deficiencies.
Reported side-effects include severe gastrointestinal discomfort, oily rectal leakage, body aches, diarrhea, flatulence with discharge and fever. Key brands: Xenical and Alli.
Lorcaserin is a selective serotonin 2c receptor agonist, approved by the FDA in 2012 for weight management. It affects chemical signals in the brain that control appetite, helping you to feel full by eating smaller meals. Lorcaserin is used together with diet and exercise to treat obesity.
A 2019 systematic review based on 9,452 patients showed favorable effects on blood pressure, heart rate and metabolic syndrome.
Commonly reported side effects of lorcaserin include: headache, euphoria, serotonin syndrome, nausea, vomiting, constipation, diarrhea, fatigue, upper respiratory tract infection, rash, urinary tract infections, back pain and dizziness. Key brands: Belviq, Belviq XR.
Liraglutide induces weight loss in a population of obese patients, including those with hypertension, dyslipidemia, type 2 diabetes, and obstructive sleep apnea, and offers the benefit of improved glycemic control.
The drug delays gastric (stomach) emptying, slowing the absorption of glucose by the gut and reducing appetite. The most common side effects, which occur in more than 5%, of people, include nausea, hypoglycemia, diarrhea, constipation, vomiting, headache, dyspepsia, fatigue, dizziness, abdominal pain and increased lipase.
Gastrointestinal intolerability is also common; it was cited as the main reason for people discontinuing the drug during trials. Key brands: Victoza, Saxenda.
The best phentermine alternatives – Natural options
The best phentermine alternatives are natural ingredients that help you to reduce your appetite and calorie consumption while carrying a lower risk of side effects that come with prescription drugs.
The following are safe ingredients that work similarly to phentermine but are available without a prescription:
Glucomannan is a water-soluble, fermentable dietary fiber extracted from the tuber that contributes to weight loss in the context of an energy-restricted diet.
It appears to promote weight loss by delaying stomach emptying and producing satiety, as it sponges up water in the digestive tract, reducing the absorption of carbs and cholesterol.
What’s more, glucomannan feeds the good bacteria in your intestine, which turns it into short-chain fatty acids (proven in animal studies to protect against weight gain). A 2008 systematic review showed that Glucomannan also appears to positively affect total cholesterol, LDL cholesterol and triglycerides.
The weight-loss results achieved with glucomannan are impressive, with one study reporting that the use of glucomannan fiber alone resulted in participants losing an average of 5.5 pounds over eight weeks without additional diet or lifestyle changes.
Glucomannan is available as a supplement and in drink mixes, or can be added to food products, such as pasta and flour. It is best taken between 15 minutes and one hour before eating, with the sufficient dosage for weight loss set at 1 gram mixed with water three times a day. Side effects, while uncommon, include mild flatulence, bloating or soft stools.
Numerous studies report natural caffeine as playing a significant role in weight loss, thanks to its ability to increase calorie burn and fat breakdown.
Additionally, coffee can work as a natural appetite suppressant, further supporting weight loss.
Consuming caffeine 30 mins to 4 hours before eating may influence stomach emptying, appetite hormones and hunger levels. This effect can last through to the next meal, so people are more likely to opt for smaller portions during lunch or dinner, and throughout the day.
Caffeine may also support weight loss by helping to boost metabolism by up to 10%.
Consuming caffeine 30 mins to 4 hours before eating may influence stomach emptying, appetite hormones and hunger levels.
B vitamins play an important function in metabolism; one of its key roles is to support the body in metabolizing fats, carbohydrates and proteins.
Thiamine (B1), for example, supports the body’s cells in converting carbohydrates into energy. Sub-par levels of this, or indeed any B vitamin, means your metabolism will be operating sub-optimally, which may lead to weight gain and potentially obesity.
Cobalamin (B12) is not available through plant sources, making it more difficult for those following a vegan or even a vegetarian diet to get enough.
Choline is an essential nutrient that plays an important role in maintaining health, including adequate lipid metabolism and the transportation of cholesterol and lipids.
A 2016 study of 3,214 people confirmed that high dietary choline is closely associated with favorable body composition in humans and that low choline levels were linked to obesity.
The peel of Garcinia gummi-gutta fruit contains hydroxycitric (HCA), which may help contain weight loss properties. Animal studies also show that supplementing garcinia cambogia may reduce food intake.
Garcinia cambogia also appears to increase serotonin levels, which then communicate with the brain to produce satiety signals, making it a possible natural appetite suppressant.
Turmeric has shown potential as an anti-inflammatory agent and may support skin diseases, digestive issues, liver conditions and obesity.
With weight gain, white adipose tissue increases. Brown adipose tissue helps produce heat by burning fat. Research has found that turmeric may trigger white adipose tissue to turn brown, leading to weight and fat loss.
We have now discussed each alternative to the well-known drug phentermine, including natural options, for those looking for a safer way to lose weight.
While phentermine can be a useful short-term weight loss method, the reported side effects are many and further research is needed to rule out the worrying links with hypertension.
All this goes to show that, choosing a natural product and combining it with a diet and lifestyle change can help you achieve safe and long-lasting weight-loss.