Drugs, fitness, & body fat

Can common medications hurt your progress?

Medications are powerful things. They can actually change your body’s response to a nutrition and exercise program. Here are the common ones to look out for.

Whenever we take on new Precision Nutrition Coaching clients, we ask them about the medications they take, either regularly or occasionally. (And we always encourage our Precision Nutrition Certified fitness professionals to do the same).

This isn’t just a getting-to-know you game (although we do try to tailor each client’s program for their unique needs).

We ask because some medications may, in fact, prevent you from losing fat, gaining muscle, and/or improving your athletic performance.

In this article, we’ll give you a brief overview of the most common medications our clients are taking when they come to Precision Nutrition.

We’ll also share some of the potential side effects these medications can produce.

The pharmaceutical society

We’ve seen incredible advances in medicine and pharmacology in the last century.

The upside: In industrialized countries, we’re living longer and generally better.

We’re no longer killed or debilitated by common, curable diseases or nutritional deficiencies.

And we can alleviate many everyday complaints, such as aches and pains, upset stomach, or allergies.

The downside: We often end up taking a lot of medications to do this.

Most of us take at least one or two medications occasionally. But more and more of us are taking more and more medications chronically.

Our clients and their prescription habits

Many of our clients take some form of medication regularly when they start coaching with us.

Because women take more hormones (especially for birth control) as well as experience autoimmune diseases, migraines, anxiety, and depression more than men, female clients are more likely than men to take medication.

Over half of our female clients are on something, and often a lot of somethings. We’ve seen female clients taking ten or more medications simultaneously.

(Don’t feel too smug, gentlemen. More than one-third of you take medications too. We know you’re popping plenty of pills for your cholesterol, high blood pressure, and upset stomachs.)

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Why does medication use matter?

When you think about losing fat and gaining muscle, you might not think about the role that your medications play in getting results.

But in fact, your medication might be affecting — even actively hampering — your progress.

Here, we’ll look at some of the more common medications, and what effects they can have on your nutrition, fitness, and overall wellness.

At the end of this article, we’ll give you some suggestions about what to do next.

Important notes

First, three important cautions.

1. We do NOT recommend that you simply quit taking any suspect medications. Always discuss any changes in medication with your doctor and/or pharmacist.

2. We’re NOT saying “medications always bad, pharma-free living always good”. We know that for many folks, medications can mean the difference between a good — or functional — day and a horrible day. If you’re on medications, you probably have some well-founded concerns about your health. We’re simply offering some information that you may not have considered in making your decisions about whether to take a particular drug.

3. We do NOT cover all the potential side effects of a given medication. These side effects are just those relevant to people who are looking to lose fat, gain muscle, and/or improve their athletic performance.

What did we look at?

Medication types

Again, we compiled this list from new client intake data in our coaching programs. So this is information from thousands of people.

While our clients are taking a wide roster of medications, here are some of the most common medication types they took regularly or occasionally.

Top medication types by gender
Men Women
Insulin/glucose management
Stomach – PPI
Beta blocker
Allergy/asthma – antihistamine
Allergy/asthma – beta agonist
Hormones (testosterone)
Allergy/asthma – corticosteroid
Gout (uricosuric)
ADHD drugs
Blood thinner
Birth control
Allergy/asthma – antihistamine
Allergy/asthma – corticosteroid
Stomach – PPI
Allergy/asthma – beta agonist
Hormones (progesterone)
Hormones (estrogen)
Insulin/glucose management
Opioid painkiller
Sleep aid
Beta blocker

Medication notes

ADHD: These are typically stimulants.

Allergy/asthma: We divided these up into 3 separate categories because they work differently: antihistamines (which block histamine release), beta-agonists (which act on adrenergic receptors of the beta type, in this case typically “ramping up” heart rate and sympathetic nervous system function), and corticosteroids (which “dampen down” inflammation).

Hyperlipidemia: These types of drugs are often prescribed along with statin drugs to lower cholesterol/lipids.

Insulin/glucose management: These are drugs like Metformin that are typically prescribed for Type 2 diabetics or prediabetics with poor insulin or glucose control.

Stomach – PPI: Proton pump inhibitors (aka “acid blockers”) prescribed typically for gastro-esophageal reflux disease (GERD).

Painkillers: We’ve divided these into a few categories:

Uricosuric: This is prescribed for gout and works by increasing the excretion of uric acid in the urine.

Side effects

To figure out what would be important to our clients looking to lose fat, gain muscle, and improve their fitness or athletic performance, we divided side effects into a few categories.

Gastrointestinal: This includes things like liver function, nausea/vomiting, diarrhea/constipation, and changes in appetite or hunger.

Nervous system: This includes things like pain, dizziness, and neurologic muscle weakness.

Metabolic: This includes things like glucose and lipid (fat) processing, metabolic syndrome/Type 2 diabetes, and weight gain.

Circulatory/cardiovascular: This includes things like cardiovascular complications (e.g. heart rhythm disturbances), electrolyte regulation (e.g. sodium/potassium levels), fluid (e.g. water retention), hypertension, or blood clots.

Mental-emotional: This includes things like mood, focus, sleep, and perceived energy levels. Memory and cognition are also included, since these affect your ability to recall information (such as nutritional advice), follow instructions, focus on a plan, or make smart decisions.

Hormonal: This includes things like adrenal, thyroid, and sex hormones, which in turn affect metabolism and body composition.

Musculoskeletal: This includes things like muscle pain and weakness, cramping, or bone and soft tissue damage.

Nutrient interactions: This includes things like medication blocking vitamin or mineral absorption, or nutrient deficiencies presenting as other health problems (e.g. anemia or insomnia).

Other: This included miscellaneous side effects like increased or decreased sweating or poor body temperature regulation; FDA warnings about lactation; and ominous-sounding stuff like “purple toe syndrome” (yep, that’s a thing — who knew?).

Once we mapped out all of the relevant side effects, we were astonished to find out how much even relatively “safe” medications can impact body composition, metabolic health, and athletic performance.

We started to realize: This is some serious stuff. Our clients and coaches need to know this.

Your medication — even if it’s over-the-counter — can significantly affect your fitness, nutritional response, metabolic environment, recovery, and overall health.

A sampler of possible side effects

Here are the side effects of some of the most common medications that we’ve listed above.

We can’t give you a complete list of each and every side effect you might experience. Nor will you inevitably experience these.

Some of these side effects are due to the actions of the drugs themselves. Other side effects occur with the nutrient changes or depletions (such as alterations in the way our bodies process minerals or electrolytes).

But here are some key items to consider, based on our list of common medications.

Allergy: Antihistamines 

Along with NSAIDs, allergy medications were some of the most common OTC drugs consumed daily or regularly.

Key side effects:

Allergy: Beta agonists

Folks with allergies and asthma are likely most familiar with these as inhaler-style medications that “open up” constricted airways.

Key side effects:

Allergy: Corticosteroids

Note that these side effects are also common to corticosteroids generally, and will vary depending on dose and type.

Key side effects:

Anti-depressant/anti-anxiety drugs

Many people — especially women — are on more than one of these medication types, several of which are correlated with weight gain.

Key side effects:


Anti-hypertensive drugs typically work on the renin-angiotensin-aldosterone (RAA) system and dilate blood vessels, providing a bigger “pipe” for blood to flow through. Since the RAA system is also involved in things like fluid/electrolyte balance and cardiac regulation, anti-hypertensives can have significant side effects.

Key side effects:

Beta blockers

Beta blockers have the opposite effect as beta agonists — they inhibit particular stress chemicals such as epinephrine (adrenaline) binding to cells’ beta receptors. They’re used to treat many cardiac conditions and hypertension. The most significant effect of beta blockers for an active population is decreased exercise tolerance/endurance and hypoglycemia.

Key side effects:

Birth control drugs

The effects of birth control hormones will differ by formulation/brand, synthetic vs. bio-identical hormones, dosage, and delivery method (e.g. oral, injections, implants, transdermal, etc.). These side effects cover the most common birth control medications.

In our practice, we have found that most women taking synthetic hormones (i.e. most commercial birth control formulations) have trouble losing fat.

Key side effects:

Insulin/glucose management drugs

Coaching clients who are still solidifying good nutrition habits and regular activity, or carrying a lot of body fat, often have disrupted glucose and insulin control (as do women with PCOS), so they take drugs such as Metformin that help to regulate this. Unfortunately, this drug group may exacerbate some of the underlying problems, such as weight gain.

Key side effects:

Non-steroidal anti-inflammatories (NSAIDs)

Many people take these for everyday aches and pains as well as more chronic problems like arthritis or long-term injury recovery. Unfortunately, they have significant GI and cardiovascular side effects, and may even worsen existing musculoskeletal problems or impede healing.

Key side effects:


These “cholesterol-lowering” drugs inhibit the liver’s synthesis of cholesterol. However, because cholesterol is such an important molecule in the body, interfering with its formation can have wide-ranging effects. Particularly of concern for active people is the soft-tissue and muscular damage that can occur, but the rest of the side effects are no picnic either.

Key side effects:

Stomach: Proton pump inhibitors (PPIs)

Along with statins, proton pump inhibitors (often known as “acid reducers”) are one of the most-prescribed drugs in North America for gastro-esophageal reflux disease (GERD). Unfortunately, they can wreak havoc with the rest of the GI tract — and might even worsen the original problem.

Key side effects:

Thyroid drugs

Many people in our coaching programs — particularly women — are struggling with the weight gain and sluggishness of low thyroid function and are consequently on medication for it.

Key side effects:

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What to do

Be a careful consumer and an informed patient. Research all medication choices carefully. Your pharmacist especially can be a great resource.

If you take medication – even occasionally – double-check all of its side effects. MerckManual.com and RxList.com are helpful resources.

Treat over-the-counter medications as carefully as prescription medications. OTC doesn’t necessarily mean side-effect-free.

Double check interactions between medications and all supplements. Again, check with your pharmacist and do your own research. As you can see above, many common medications impair proper digestion and GI function as well as nutrient uptake and use. If, for example, your liver isn’t functioning properly, any other supplements you ingest may not be properly or safely metabolized. Additionally, medications may work synergistically with supplements. For instance, combining an allergy/asthma beta-agonist with a “fat burner” (which has stimulant effects) could be bad news for cardiac safety.

Recognize that medications have powerful effects on body composition, physical performance, and overall wellness. If you’re struggling to get results with a solid health and fitness program, underlying health conditions and medication use might be playing a role.

Consider getting coaching. You can often reduce medication intake by improving your nutrition and exercise habits. For some help, check out our coaching for men and women. A good coach can help work with your current medications to help you get the best possible results for your body, no matter what you’re working with.

If you work in fitness, consider learning more. Through our Precision Nutrition Certification, we teach motivated fitness professionals the art and science of nutrition coaching. Including how to work with clients with special medical conditions, how to address medication use, and so much more.

Whatever the outcome you’re getting from your fitness and nutrition program, keep doing the healthy behaviors that truly matter. The better your general fitness, health, and nutrition, often the fewer medications you’ll need to take.

Want help?

If you’d like some help with your own nutrition and exercise program, even if you’re on one of the medications discussed above, that’s what we’re here for.

We accept a small number of new clients every 6 months, and the spots in our coaching programs typically sell out in hours.

However, those motivated enough to put themselves on the presale list get to register 24 hours before everyone else. Plus, they receive a big discount at registration.

So put your name on the list below — because, as always, spots are first come, first served, and when they’re gone, they’re gone.

Don't miss out! Get on the Precision Nutrition Coaching presale list today!

Soon we’re taking a small group of new clients and getting them in the best shape of their lives. Spots are first-come, first-served and typically sell out in minutes.

Get on the presale list to register at a discount 24 hours before spots open to the general public.

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