Twitter Thread: https://x.com/_TomHoward/status/1869878870851117183

My Experience

From January 2024 through September 2024 I have successfully lost 95 pounds, starting at 300 pounds and ending up at 205 pounds.

I started with Keto Carnivore for about 4 months, and then started GLP1s in April as my travels would be breaking my habits and routines. I wrote about my experience with Retatrutide, the next-gen GLP1.

During that time I not only maintained my muscle mass, but increased my muscle mass by a few pounds, meaning all my weight loss was fat and water.

From InBody
Body Fat: 40.8% > 20.8%
Skeletal Muscle Mass: 95.9lbs > 97.9lbs

GLP1 Protocol Overview

Here is everything I will cover, which also serves as a tldr; if you want the quick answer to the headline:

• What Are GLP1s?

• The wrong approach to GLP1s

• The right approach to GLP1s

• The GLP1 Protocol

  • 1. Find your minimum viable dose

  • 2. Increase Water Intake and Electrolytes

  • 3. Switch To High Protein Low Carb Diet

  • 4. Get Exercise

  • 5. Have a Plan For Stopping

• Measuring Success and Monitoring

• Winning

What are GLP1s?

Am going to keep this section brief, but a quick primer.

GLP1s help treat Type 2 Diabetes, Metabolic Disorder, Obesity, and a host of other metabolic related diseases. They have gotten very popular as a weight loss drug as they are incredibly effective. Many people find them life changing.

GLP1 stands for Glucagon-like Peptide-1, and the drugs are considered GLP-1 Receptor Agonists, that is they stimulate the receptors.

This class of drugs are actually called “Incretin Mimetics”, but I’ll be using the term “GLP1” to refer to all incretin mimetics just because it is the most popular term to describe these, besides “Ozempic.”

There are actually three types of incretin mimetics (so far), with GLP-1RA being the subset that are “single agonist”:

1. GLP-1 Receptor Agonists
   Examples: Semaglutide (Ozempic, Wegovy), Liraglutide (Saxenda).
   Mechanism: Mimic the action of the GLP-1 hormone, enhancing insulin secretion, reducing glucagon release, slowing gastric emptying, and decreasing appetite.

2. Dual Agonists (GLP-1/GIP RAs):
   Example: Tirzepatide (Mounjaro, Zepbound).
   Mechanism: Activates both GLP-1 and GIP (Glucose-dependent Insulinotropic Polypeptide) receptors. GIP enhances insulin secretion and has additional metabolic effects when combined with GLP-1 activation.

3. Triple Agonists (GLP-1/GIP/Glucagon RAs):
   Example: Retatrutide (in development, I wrote about it here).
   Mechanism: Combines GLP-1 and GIP receptor activation with glucagon receptor agonism. The glucagon pathway promotes fat metabolism and energy expenditure.

As you can see all of them are GLP-1 Receptor Agonists and the newer versions activate other receptors with the intention of balancing out the effects. For instance, the dual agonists have much less instances of nausea and hypoglycemia than the single agonist.

The Wrong Approach To GLP1s

These are powerful tools, and like any tool can be used incorrectly. For instance if we gave people cars and just let them drive with zero training, we would have chaos on the roads, not because cars are inherently bad, but because none of those drivers had learned to use them correctly!

Similarly, GLP1s get negative attention from both patients and doctors using them incorrectly.

They are not magically hands free drugs that you just take and completely forget about. They are not something you should aim to stay on for life. They are not an excuse to skip the work of becoming healthy.

These are NOT the answer to childhood obesity.

If you take them continuously without any plan, you will probably end up contracting the bad side effects that grab people’s attention.

So here’s how to do it right:

The right approach to GLP1s

Depending on where you are starting from, your strategy may be different.

For someone who is morbidly obese, possibly Diabetic or with other diseases, think of this as an escape hatch from the downward spiral of severe obesity.

At this point, you likely have something called “leptin resistance.” Leptin is the signal that tells your brain you are full, and fat cells produce a lot of leptin. When you flood your brain with leptin, it eventually gets overloaded and starts ignoring the leptin signal. This means that instead of feeling full from leptin, you never feel full at all! The fullness signal in your brain is broken. This makes you hungry ALL THE TIME and you can’t get enough food, which causes you to continue gaining weight.

You also probably have or are developing insulin resistance, which means your body isn’t utilizing your blood glucose correctly, leading to fat gain and the development of diabetes.

You probably have trouble exercising. If you weigh a lot it’s a lot of effort to just do a squat or a pushup! I know because I’ve been there. Compared to others in the gym I was working as if I had an extra 100 pounds strapped onto me. It's hard.

You probably have trouble managing your cravings, especially for sweet or savory foods, which means you end up eating lots of sugary, carby or fatty foods.

There are parts of this you may not want to change or don’t think you can change. That’s ok, this isn’t going to get fixed all at once.

What the GLP1s give you, is a tool, an escape hatch from these very powerful chemicals telling you to eat all the time, sapping all your energy for anything else.

You should not use GLP1s long term without changing any of the above, but you should get started even if you don’t want to make any changes right away.

Once you get started and you get used to the GLP1s, you will start to notice that the cravings are going away, that you have more willpower to make your own choices and stick with them. You will start to notice that you feel better, and you have more energy for activities.

This is how you can use these to change your habits and completely reverse your health condition, usually within 1-2 years.

Start the GLP1, then layer in your habit changes over time.

Or maybe you aren’t in an extreme situation. Perhaps you are getting older, you have lots of work responsibilities, you have a family to take care of, you have high stress and no time. You’ve put on an extra 20-30 pounds you want to lose.

You know you need to take care of your health, you know how to eat right and exercise, but you don’t have the bandwidth.

GLP1s are a tool you can use! Some people refer to it as a “willpower drug” instead of a weight loss drug. This is because it enables you to look at a carby snack you know you shouldn’t be eating, and just ignore it with zero craving.

The stress or convenience of eating fades away, and you only eat what you plan to eat on the schedule you make.

GLP1s eliminate what is being referred to as “food noise”, which are the constant intrusive thoughts about what you want to eat, when to eat next, how to get that food you really like, and so forth. Those thoughts go away and clear your mind for your other priorities in life.

Some people who are already at their ideal body fat levels are taking GLP1s as well, due to the increase in will power, decrease in intrusive thoughts, and potential longevity benefits. If this is you, this protocol will work for you as well.

The GLP1 Protocol

For folks starting out with high obesity, I’ve put these in order that I think will be most helpful to layer them in. You may want to make the changes a month or two apart. You may want to do them weeks or days apart. You may want to do them in a different order, that's fine.

For folks who are not starting with high obesity and are looking to lose a bit and get back to previous good health habits, you can accelerate the plan and even do it all from day 1 if you feel up to it.

1. Find your minimum viable dose

Each GLP1 comes with instructions for dosing. Many don’t follow them exactly. Some people respond to them strongly, some don’t respond at all. There is a ramp up period as your body adjusts to it, which may take 2-4 weeks. If you feel nothing, you may want to increase the dose faster. If you feel it too strongly, you may want to decrease the dose.

The feeling you are looking to get to:

• No more “food noise” which is the constant thought process in your mind about eating. When will you eat next, what will you eat, how will you get it, maybe you should have some now, etc. That should go away.

• You can eat a meal, but you don’t feel the need to finish it. If you can’t eat at all then its too much (but the first few days may feel like this).

• No more cravings. The late night urge to snack goes away. You can see French fries or a cupcake and not feel the need to eat it immediately.

• A little bit of nausea is ok, at first. In the beginning you might get nauseous after eating, or even from looking at food. You probably over ate and this is the negative feedback loop teaching you to not overeat. If this persists after a few weeks or is very strong then maybe your dose is too strong.

Some side effects or signs you took too much:

• Hypoglycemia or low blood sugar is very common in the initial adjustment phase. Low grade hypoglycemia is very uncomfortable but generally passes shortly. Severe hypoglycemia is life threatening. Typically severe hypoglycemia only happens when people accidentally overdose. That said you should read the medical literature on hypoglycemia symptoms and treatment so you can be aware of it. The quickest way to fix it is by drinking something sweet. I keep packets of Pocari Sweat (an isotonic drink) handy just in case. Personally I’ve found this goes away after the first few days of starting. https://www.mayoclinic.org/diseases-conditions/hypoglycemia/symptoms-causes/syc-20373685

• Non-stop nausea or vomiting. Some nausea around eating is common, but constant nausea is not, and probably means the dose is too high. If it’s persistent you may want to seek medical care.

• Diarrhea or gastrointestinal problems. This is common though may not be something to be urgently fixed, depending on severity. I’ve mostly seen this resolve itself with dietary changes, addressed below.

Once you find your minimum effective dose, only increase it if you need to! If it stops working, meaning you aren’t getting the target feelings above and your weight isn’t decreasing, you may need to increase. However you can only increase this so much before you hit the ceiling of what works safely, so don’t rush it.

2. Increase Water Intake and Electrolytes

You can do this right away when you start. GLP1s decrease your water retention, especially the dual and triple agonists, so you’ll want to drink significantly more water to make up for it.

Additionally you’ll want to take extra electrolytes as they are getting flushed away and not being replenished with your normal food intake, since you are eating less!

I like LMNT and SALTT Clean Slate, but I usually just mix my own. I aim for about 5-8g of added electrolytes daily.

Some people encounter fatigue after weeks or months on GLP1s, and partially that is due to the caloric deficit, but oftentimes is dehydration and electrolyte loss, which they can fix immediately by drinking more water and electrolytes.

3. Switch To High Protein Low Carb Diet

Depending on your dietary habits and preferences, you can do this all at once or layer it in over time.

One of the most common side effects of caloric restriction diets (which GLP1s are making you do), is muscle loss. There doesn't seem to be any evidence that GLP1s directly make you lose muscle, other than the fact that they are incredibly effective at keeping people on a caloric restriction diet.

Some reports are saying that 40% of GLP1 weight loss is from muscle loss. Well myself and many others have done this and little to no muscle mass. I’ve even gained some muscle.

The solution is simple: eat a lot of protein and do some light exercise to keep your muscles active (more on that below).

For protein aim for 0.6g - 1g per pound of body weight. You’ll probably need protein powder to do this (I use True Nutrition). I also recommend lots of beef as it contains lots of essential amino acids for muscle synthesis and gut health. Other meats are great too.

In the protein shakes, add Branch Chain Amino Acids (BCAA) which are the amino acids used in muscle synthesis.

Next try to eliminate carbs and sugars as much as possible. The more sugary something is, the more stressful it is on your metabolic system, causing blood sugar spikes, insulin spikes, and other downstream effects.

The GLP1s will help you handle carbs much better, but from what I’ve seen, most of the folks experiencing gastrointestinal side effects are continuing to eat lots of carbs, sodas, and processed foods that are just not good for the body.

Use the GLP1 as a tool to drop the cravings for these types of foods. Now is your opportunity!

For fats, go for low-moderate amounts of healthy fats. Too much will make you sick on GLP1s but you also need healthy fats to be healthy.

4. Get Exercise

When you are ready to start, getting exercise will help you maximize the benefits of GLP1s and eliminate the side effects.

To prevent muscle wasting, high protein along with muscle activation is required, so just starting with some light cardio that works your whole body goes a long way.

If you know what you are doing already, just go to town on this. Cardio and Strength training are great.

If you are new to this, start with going for walks and work up to other cardio. Most people who are very overweight have bad knees, so running is usually not a good option. Biking (road or stationary), Rowing, Elliptical, Swimming, are all great options.

Next you’ll want to start doing some resistance or weight training. If you don’t know what you are doing, I recommend taking a class or hiring a trainer. With consistent weight training and protein intake you can actually put on a little bit of muscle while on GLP1s!

Once you get down to a healthier body fat level and start thinking about coming off the GLP1, the muscle you have will help you metabolize carbs and food and keep rebound weight off, as well as help prevent many diseases.

5. Have a Plan For Stopping

GLP1s are known for “rebound” weight gain, but this does not have to be the case! Have a plan in place so you know what to do when it is time to come off them.

There will always be some “rebound” solely due to your water retention returning, which can be as much as 5 pounds within days! Then your appetite will start to increase as it wears off, and this is where your new habits and plan will prevent you from going back to where you were.

Remember that the GLP1 tool is an escape hatch to get to a healthier place and stay there.

If you come off before you hit a healthy body fat target, you may still be getting some of the negative effects of leptin and insulin resistance, though not as strongly as before.

Many folks who have used GLP1s and then stopped, have reported that the GLP1 has “rewired” their brain around eating habits. They no longer have the cravings they used to have, they no longer overeat like they used to.

If you have used the GLP1 as the willpower tool it can be, you will have completely reformed your diet and lifestyle.

It is critical that you stick to your ideal diet in that first month coming off of GLP1s. If you change your diet at the same time as you stop GLP1s, you will be more likely to relapse to old habits.

If you stick to your diet (and exercise) plan, even if you are eating more calories, you will minimize the rebound effect, which is strongest in the first month, and can maintain those good habits for the rest of your life.

From experience, I recommend a 1-2 month transition period before trying to do anything new. Can you aim to continue fat loss without GLP1, which will require more willpower (probably easiest on a keto/high protein diet). You can aim to stabilize your weight and diet which will be easier.

I would not recommend going straight for a muscle gaining protocol which typically requires a large calorie increase, making it easier to overeat during the rebound period. Give yourself some rest.

Monitoring and Measuring for Success

As you embark on this weight loss experiment, you will need a few tools to keep yourself honest and keep track of your success or side effects.

Body Weight

This is the most basic and straightforward one. You need a body weight scale that you ideally measure at the same time every day before eating or even drinking water. I have one in the bathroom and I measure myself immediately after waking up and peeing, before I have a sip of water. This lets me see my daily progress.

Body weight is tricky though as it’s susceptible to water fluctuations or even muscle fluctuations. Don't get hung up on the day to day change and look more at the weekly and monthly trends.

Body Composition

Body composition is trickier as it’s difficult to measure. But it’s important to know what % of your body mass is fat, muscle, bone and water. Your real goal should not be weight loss but body fat loss and muscle gain!

At Home - body composition scales are notoriously inaccurate, but can give you a sense of overall trends. I like the Withings Body Scan.

In the Gym - almost every gym these days has some sort of scanner, such as an InBody. This is also the same tech as the in-home scale but slightly more reliable. Some gyms have more advanced machines such as Styku that use infrared scans

Medical - Dexascans are considered the gold standard in body composition measurement, but they are expensive and require an X-ray. I try to do them every 6 months to establish a baseline against the InBody and Withings.

Blood Glucose

Watching your blood glucose will help you learn what spikes your blood sugar and what does not. A Continuous Glucose Monitor is the easiest way to monitor this, but also the least accurate. If you want to monitor for low or high blood sugar, the finger prick monitors are more accurate.

Some Blood Glucose Monitors: Stelo, Nutrisense, Libre 3

Finger Prick: Keto Mojo, Generic

Blood Ketones

Want to do the Keto diet while on the GLP1? I did Keto-Carnivore and highly recommend it. A continuous ketone monitor will help dial this diet in, and I’ve found them to be almost as accurate as the finger prick monitor.

SiBio CKM: US Only, Intl Non-US

Finger Prick: Keto Mojo

Blood Tests

Likely you are working with a doctor on the GLP1. They should have you getting regular blood tests to monitor for any unwanted side effects. If they aren’t you may want to find another doctor.

You can also order and check your own blood work. In the future I may cover what to look out for in blood work for GLP1s specifically. If you are doing your own research and just want to order your own labs, here are some options.

Done for you: Function Health

Order your own: UltraLabs, Own Your Labs, Jason Health

Winning

Remember this is a tool to help you achieve your health goals. It does not have to be a permanent solution to stay on for life. Set a body composition goal and be ready to get off the GLP1 once you hit your target! Lose fat, get fit, don’t die.

If you want to go more in depth on GLP1s, I’ve written an article on Retatrutide here, and may write a more detailed GLP1 guide.

Please leave questions in the comments, especially around side effects, and I will maintain a running FAQ.

Retweet: https://x.com/_TomHoward/status/1869878870851117183

Thanks to Raghav Gulati⁩ for his feedback and the many folks I’ve spoken to about using GLP1s.

After trying the new "3rd generation" GLP-1, Retatrutide, for 2 months, I find it much more effective than Tirzepatide and with less side effects (namely fatigue).

My weight-loss has been about the same, if not slightly quicker, but more importantly, my energy levels are much higher, and most interestingly, my blood ketone baseline has been higher.

On Tirzepatide, while effective, I would get fatigued if I didn't carefully manage my energy state by doing things like drinking extra water, making sure I ate on time, and supplementing with exogenous ketones.

I am sharing all the details on exactly where and how Retatrutide was used in this journey, but first a bit of background on Retatrutide...

What is Retatrutide?

The "GLP-1" class of peptides has a few different types of peptides:

Gen 1 - Semaglutide, also known as Ozempic or WeGovy, is a single mechanism peptide. This is a GLP-1 (glucagon-like peptide-1) receptor agonist. It works by mimicking the effects of GLP-1, a hormone that promotes insulin release, reduces appetite, slows gastric emptying, and regulates blood sugar.

Gen 2 - Tirzepatide, also known as Mounjaro, is a double mechanism peptide. It is both a GLP-1 and GIP (glucose-dependent insulinotropic polypeptide) receptor agonist. GIP enhances insulin secretion and may play a role in lipid metabolism, synergistically with GLP-1 effects.

Gen 3 - Retatrutide is the new peptide that is still undergoing phase 3 (final) clinical trials with the FDA. This is a triple agonist targeting GLP-1, GIP, and glucagon receptors. Glucagon receptor activation can enhance energy expenditure and further promote fat loss. This last point is key when it comes to increasing blood ketone levels.

The Hunger Hormones - Insulin and Glucagon

Insulin is the hormone that facilitates the entry of glucose into our cells, where it is used for energy. It also signals to the liver to convert glucose into glycogen for short term storage, or fat for long term storage.

When there is a lot of insulin circulating in the blood, one feels full, bloated, or even nauseous. If you've ever eaten way to much, you are familiar with this feeling.

The GLP1 and GIP mechanisms in Semaglutide and Tirzepatide encourage a stronger insulin response to blood glucose, increasing the insulin response to glucose entering the blood stream, and increasing the sensitivity of our cells to absorb glucose.

This is the main mechanism of weight-loss for these two peptides, use glucose more effectively and make one feel full quicker.

Glucagon is the other hormone that helps our cells get energy. When insulin levels fall in response to a lack of blood sugar, the pancreas secretes Glucagon, which signals to the liver to do the opposite of insulin: mobilize the stored glycogen for energy, and when that runs out, activate the long term fat storage as an energy source.

This is the mechanism that activates ketosis! A shortage of glucose (carbs) triggers Glucagon to signal to the liver to convert stored body fat into ketones, to be used as a backup energy source.

One can see why adding this 3rd mechanism would be very beneficial for fat loss, as not only is insulin being more effective, but glucagon is being stimulated as well.

As I was studying the mechanisms of ketosis and the glucagon/insulin relationship, I was quite excited to come across Retatrutide's Glucagon agonist mechanism, as I hypothesized it would enable an easier and more consistent ketogenic state, which would also mitigate the low energy issues with Tirzepatide.

Results of the Phase 2 Trial

Retatrutide is patented by Eli Lilly, who has completed a phase 2 clinical trial with the FDA: https://www.nejm.org/doi/full/10.1056/NEJMoa2301972

I read through the entire trial to see if I could confirm my hypothesis that the Glucagon agonist would increase weight-loss and induce ketosis, as well as study any adverse effects.

The results on weight loss seemed quite significant, a roughly 20% increase vs. Tirzepatide or Semaglutide. Unfortunately the study did not seem to measure ketone levels and gave no indications around ketosis.

Since it is a relatively new and untested compound, I wanted to check if there were new side effects vs. existing GLP1s peptides.

I studied the adverse event table from the trial: https://www.nejm.org/doi/full/10.1056/NEJMoa2301972#ap2

Most concerning was 1 death and 13 serious adverse events, out of 337 total. Ok well the 1 death was from drowning and concluded to be unrelated. There were several serious cardiac events however, including among the placebo group. Ok good time to revisit the selection criteria for the study:

Ok, so the participants had to be extremely obese, or obese with a pre-existing heart condition. Additionally the average age was around 48, so skewed to the older side. Given the selection criteria and sample size of 337 split into 7 groups, I personally do not find the data to be conclusive around whether the cardiac incidents were related to Retatrutide or not.

Additionally, there were 19 reports of Cardiac Arrhythmia out of the 337 participants. Given the participants were selected with pre-existing cardiovascular conditions, how much of an impact did Retatrutide have on this effect?

Again, the smaller sample size skews the data a bit, but we can see the average rate of arrhythmia in the 1mg-4mg groups is roughly the same or slightly higher than placebo. However in the higher dose groups, 8mg-12mg, the Arrhythmia incidents seemed to increase substantially. Ok, so this is something to keep an eye on.

Hypothesis: some of the causes of arrhythmia include electrolyte shortage, low blood sugar, and glycogen shortage. Given that Insulin moves glucose out of your blood stream, and Glucagon mobilizes your glycogen reserves, its quite possible that this is causing a shortage of glucose or glycogen energy shortage for the heart at higher doses. Finding ways to mitigate this would be interesting, but probably something one would want to test in rats first.

EDIT: The above hypothesis is probably incorrect.

It turns out that Glucagon, among other things, directly stimulates the heart, and is even used in emergency room contexts to get the heart going again. It seems likely this is the cause of increased heart rate and arrhythmia at higher doses.

To monitor for potential Arrhythmia, things I watch out for:

• Increased heart rate, especially resting heart rate, lowered HRV, increased blood pressure, heart palpitations

• Getting dizzy easily during physical activity

• Shortness of breath, chest pain or discomfort, fainting

• Heart monitoring devices that can check for arrhythmia

Ultimately it probably makes sense to stay away from higher doses until it is better studied.

What about other adverse reactions?

• Hypoglycemia - "No cases of clinically significant hypoglycemia." Regardless I personally always watch for mild hypoglycemia, especially when starting or increasing doses of GLP1s, as the increased insulin levels can remove blood sugar quickly.

• Pancreatitis - as Glucagon is secreted by the pancreas, this may be putting extra strain on the pancreas and is something I wanted to watch out for. 1 case of pancreatitis in the trial.

  • abdominal pain, characteristic of acute pancreatitis (that is, epigastric pain radiating to the back, often associated with nausea and vomiting)

  • serum amylase (total, pancreatic, or both) and/or lipase ≥3X ULN

• Liver - as all 3 mechanisms affect the liver, I wanted to keep an eye on this as well.

  • "Transient increases in alanine aminotransferase (ALT) levels to more than 3 times the upper limit of the normal range occurred in 1% of the participants who received retatrutide"

• Heart

  • The heart rate increased in a dose-dependent manner with retatrutide up to 24 weeks and then declined thereafter

  • Avg heart rate increase was 10bps, compared to 3bps on Tirzepatide

After digesting all this, I was comfortable with replacing Tirzepatide with Retatrutide and seeing if it would indeed increase my blood ketones and overall energy.

Starting on Retatrutide

For these GLP1s, I personally prefer to dose daily to reduce any "swings" in effectiveness and have more fine grained control over dosing. I started this after trying Tirzepatide on weekly dose and finding that I'd rebound at the end of the week due to the ~5 day half life.

For my GLP1 doses, I will include the daily (weekly) dose in that format.

For reference, the dose schedule for Tirzepatide vs. the dose schedule used in the Retatrutide trial

Since I was already on Tirzepatide 2mg daily (14mg weekly), I hypothesized that I would already have a tolerance to the first 2 mechanisms of Retatrutide but no tolerance to the 3rd mechanism. So I designed a transition protocol for myself to switch over for a month.

First I wanted to test if I would be a hyper responder to Retatrutide or be sensitive to any side effects, so I did a quick ramp up in small doses, aiming for a weekly equivalent of about 4mg. At the same time I dialed down tirzepatide from 2mg daily to 1.5mg daily (10.5mg weekly):

No adverse affects, so I ramped down Tirzepatide to 1mg daily (7mg weekly), and increased Retatrutide to 1mg daily (7mg weekly).

That week I was HUNGRY. Retatrutide works a bit differently, and apparently most people experience an INCREASE in hunger when they first start it. However I got full and stayed full much quicker than even on Tirzepatitide, and reports I've read from others say similarly.

After two weeks, I started to feel the appetite suppressant effect kick in, so I increased my Retatrutide dose to 1.5mg daily (10.5mg weekly) and discontinued Tirzepatide entirely. This dose has been the same for the rest of this dataset.

Since I've been in this stable state with Retatrutide, I noticed a very clear energy increase vs. Tirzepatide.

The appetite suppressant effect is there to the point where I would forget to have a meal. Supplementing with protein powder and carrying around a bunch of Chomps beef jerky has been critical to hitting my protein target and maintaining muscle.

If I missed a meal on Tirzepatide, I would get really fatigued and cranky, not so on Retatrutide. And I was able to confirm using my Continuous Ketone Monitor that indeed, my average ketone levels were higher! On Tirzepatitide I would typically hover around 0.5 mmol/L, on Retatruide 1-1.5 mmol/L was more typical.

After the transition period, weight loss accelerated again, resulting in a 17 pound loss in a month.

Adverse effects

Surprisingly very little negative effects! I did not notice any change in my RHR, I have no more fatigue, and I do not experience any of the other negative effects. I do typically have a minor hypoglycemic event when I increase the dose, as I do on other GLP1s, which I pre-empt by taking exogenous ketones and having some protein handy. (the proper way to treat this is with sugar water, but I prefer not to spike my glucose)

EDIT: As I increased my dose up to 10mg-14mg weekly I started to notice the effects of Arrhythmia. I ended up discontinuing it while I reset my tolerance and intend to return to it.

Conclusion

As I have validated that Retatrutide meets all my goals of weight loss, high energy, and minimal side effects, I plan to continue using Retatrutide until my body fat target has been met. Tirzepatide was great too, but managing the fatigue was an ongoing effort.

It is important to note that throughout this entire experiment, I have maintained a mostly carnivore diet of meat, eggs, dairy, and a bit of green vegetables. My protein target is 200g/day and my carb target is 0g/day. I also make sure to intake electrolytes and other supplements as one would on a typical keto diet. I also exercise at least 3x per week.

Please note that nothing in this post is advice of any sort. Its especially definitely not medical advice. This is sharing my own research and experiences. Don't do anything I do.

Follow me on Twitter for more bio-hacking experiments: https://x.com/_TomHoward

EDIT: PS. Prudent Comment