At 45, keeping extra weight off feels like a bigger project every year.

Losing it once it settles in has been even more frustrating.

I started noticing that change around 40. By the time I tried Bioinfinity Lab Retatrutide, I weighed approximately 215 pounds and wanted to get leaner while holding onto the muscle I had worked to build.

Over three months, I lost about 20 pounds, finishing around 195. I also felt that I retained most of my muscle, although I do not have body-composition measurements to confirm that impression.

For me, the results were amazing.

The appetite suppression was dramatic, my order arrived quickly, and the overall experience gave me plenty to talk about.

There were downsides, too, including the cost and times when eating enough became a challenge.

Here is my experience, alongside what published research actually tells us about Retatrutide.

Disclosure: I have an affiliate relationship with Bioinfinity and may earn a commission from qualifying purchases.

This review describes my personal experience, not typical results or medical advice.

Retatrutide remains investigational and is not FDA-approved.

The FDA warns that unapproved versions have not undergone its review for safety, effectiveness, and quality. ¹

Who Is Bioinfinity Lab?

Bioinfinity Lab, currently branded BioInfinity, supplies research compounds.

Its website identifies the business as BioInfinity LLC, lists a Manhattan address, and describes its products as intended for laboratory research rather than human consumption.

The company emphasizes batch-specific certificates of analysis, or COAs, and says its analytical documentation includes HPLC and mass spectrometry.

Its About page discusses transparency and consistency but does not identify a founder or provide a founding year. ²

That leaves some gaps in the company history.

I would rather acknowledge those gaps than give you an impressive-sounding background that I cannot verify.

For this review, the clearest things I can personally discuss are my order, delivery, and experience.

Company testing claims deserve their own scrutiny; they are not something I can confirm by how strongly a product feels.

I would want any certificate to match the relevant batch and clearly identify what was tested.

A purity result alone does not establish that a research product is safe for human use.

What Is Retatrutide, And Why Is It Getting Attention?

Retatrutide, also known as LY3437943, activates three hormone receptors: GLP-1, GIP, and glucagon.

That is why researchers describe it as a triple receptor agonist. ³

In everyday language, it is a compound being studied for its effects on metabolic processes and body weight.

It is quite different from the stimulant-heavy pre-workouts I used previously.

One important study was a 2023 phase 2 trial involving 338 adults.

After 48 weeks, the highest-dose Retatrutide group had an average weight reduction of 24.2%, compared with 2.1% in the placebo group. ⁴

That helps explain the interest, but those figures need context.

The researchers studied an investigational drug under clinical supervision, not Bioinfinity Lab Retatrutide purchased online.

The trial also lasted substantially longer than my three-month experience.

Its results cannot verify the contents of my vial or tell another reader what outcome to expect.

The studies linked below are indexed on NIH’s PubMed website.

Their inclusion there does not represent an NIH endorsement of Bioinfinity or its products.

My Personal Retatrutide Test Results

Why I Started Looking

Around 40, keeping my weight where I wanted it became more difficult.

By 45, I was tired of feeling like losing a few pounds required an increasingly frustrating effort.

For years, I had relied on pre-workout supplements with strong stimulants.

Blood-pressure issues eventually led me to stop using them, and I became interested in something that addressed appetite.

My mom had been taking Retatrutide for about six months and reporting awesome results.

Her experience got my attention, and researching the compound led me to Bioinfinity Lab.

That family experience explains my interest, but it does not establish medical suitability.

Moving away from stimulants does not automatically make a different drug appropriate for someone with blood-pressure concerns.

Ordering And The First Few Days

I ordered a 30 mg vial and received it within a couple of days.

From a delivery standpoint, my experience was straightforward.

There were no human dosing or usage instructions.

I used ChatGPT to help formulate a plan around my age, weight, and goals, but that was not medical supervision, and an AI-generated plan cannot establish safe use.

I would not recommend relying on a chatbot for that decision.

This review does not provide a dosing or injection protocol.

Within a couple of days, I noticed a dramatic drop in appetite.

It was easily the most obvious change during the early part of my experience.

Honestly, it sometimes worked almost too well.

There were times when I felt like I had to force myself to eat, which deserves attention rather than being treated as a bonus.

My Weight After Three Months

I started around 215 pounds and finished near 195. That works out to approximately 20 pounds lost, or about 9% of my starting weight.

I was particularly pleased that I felt I retained most of my muscle.

However, my impression cannot tell us how much of the weight change came from fat, lean tissue, or water.

This was an individual experience, not a controlled experiment.

It cannot separate the product’s effects from changes in food intake, activity, or other factors.

What Research Says About Muscle And Fat Loss

A 2025 Retatrutide substudy examined body composition in adults with type 2 diabetes using DXA scans.

Researchers reported reductions in body fat and found that the proportion of lean mass lost relative to overall weight loss was similar to other obesity treatments. ⁵

That is useful context, but it does not mean Retatrutide prevents muscle loss.

It also cannot confirm my impression that I kept most of my muscle.

I am happy with my result without turning it into a promise of losing only fat.

Those are different claims.

Things I Liked About Bioinfinity Lab Retatrutide

The Appetite Change Was Noticeable

Appetite was what I wanted help with, and it was where I noticed the biggest difference.

I did not finish three months wondering whether anything had changed.

The scale moved meaningfully, too.

After being frustrated with my weight, seeing approximately 20 pounds come off felt like a significant personal result.

I Noticed It Quickly

For me, the appetite change appeared within a couple of days.

I appreciated noticing something early instead of spending weeks trying to interpret a subtle difference.

That timeline belongs to my experience.

It is not a guaranteed onset time, and a fast response does not establish product quality or safety.

It Felt Stronger Than Other Brands I Had Tried

I had previously tried Retatrutide from Verified Peptides and Peptide Sciences.

Subjectively, Bioinfinity’s product felt more potent to me, especially in terms of appetite suppression.

That is a personal comparison, not a laboratory finding.

I cannot use it to conclude that another brand was underdosed or that Bioinfinity has superior purity.

Delivery Was Fast

My order arrived within a couple of days, which I appreciated.

Shipping is one part of the customer experience I can describe directly, even though it does not tell us what is inside a vial.

Things I Did Not Like

The Price Is Significant

Bioinfinity Lab Retatrutide is expensive.

When checked on October 9, 2026, the product page displayed a $375 regular price and a $225 sale price for the 30 mg size, under the Retatrutide or GLP3-R listing. ⁶

I had also found the coupon code PEP20 advertised for 20% off.I have not verified whether it currently works or combines with the displayed sale, so I would not promise an additional discount.

Even at a reduced price, the cost deserves consideration.

One vial’s price also does not establish a monthly treatment cost.

Weight Maintenance Is Still A Question

Losing weight over three months does not tell me what happens over the next year.

That is an important limitation of this review.

Research on a different medication, semaglutide, illustrates why maintenance deserves attention.

In the STEP 1 trial extension, participants regained roughly two-thirds of their prior weight loss during the year after semaglutide and the study’s lifestyle intervention were stopped. ⁷

That does not predict exactly what will happen after Retatrutide.

It also does not prove that every person needs indefinite treatment.

For me, the takeaway is that a maintenance plan matters.

It is something to discuss with a clinician rather than assume the initial result will automatically last.

There Are No Human Usage Directions

The lack of instructions can be frustrating, but the research-use designation is not a minor technicality.

This is not an approved medicine supplied with a patient treatment plan.

My experience with ordering a vial should not be confused with receiving medical care.

A seller’s product page cannot replace an assessment of health history and treatment suitability.

Appetite Suppression Can Go Too Far

Having to force myself to eat was the clearest downside in my own account.

Less hunger is one thing; struggling to eat enough is another.

The 2023 phase 2 trial also reported gastrointestinal side effects, mostly mild to moderate, and dose-related increases in heart rate.

Those findings matter, particularly given my history of blood-pressure concerns. ⁴

My positive weight result does not cancel out those risks.

Nor does it establish long-term safety.

Bioinfinity Lab Retatrutide FAQs

Is Bioinfinity Lab Retatrutide FDA-Approved?

No.

Retatrutide is not FDA-approved, and a seller’s testing certificate does not change that status. ¹

Did I Lose 20 Pounds Of Pure Fat?

I lost approximately 20 pounds of body weight.

I felt that I retained most of my muscle, but I cannot quantify the fat and lean-tissue changes.

Does My Experience Predict Your Results?

No.

One person’s account cannot establish a typical outcome, confirm a safe regimen, or show whether a product is appropriate for someone else.

My Recommendation

I am pleased with what I experienced over those three months.

Going from roughly 215 pounds to 195 was meaningful, and the appetite change was hard to miss.

My order arrived quickly, and Bioinfinity’s product felt stronger than the other brands I had tried.

The price and sometimes excessive appetite suppression were the biggest practical negatives.

If you are another guy in his mid-40s struggling with weight, I understand why this experience would catch your attention.

I recommend discussing appetite and weight-management options with a qualified clinician, including approved treatments where appropriate.

My personal results felt amazing.

They do not establish that Bioinfinity’s research-only product is safe to self-administer or equivalent to the Retatrutide studied in clinical trials.

References

1. US Food and Drug Administration.
   
   FDA’s concerns with unapproved GLP-1 drugs used for weight loss.
   
   Accessed October 9, 2026. FDA.
2. BioInfinity. About us.
   
   Accessed October 9, 2026. Company source.
3. Coskun T, Urva S, Roell WC, et al.
   
   LY3437943, a novel triple glucagon, GIP, and GLP-1 receptor agonist for glycemic control and weight loss: from discovery to clinical proof of concept. Cell Metab. 2022;34(9):1234-1247.e9. doi:10.1016/j.cmet.2022.07.013. PubMed.
4. Jastreboff AM, Kaplan LM, Frías JP, et al.
   
   Triple-hormone-receptor agonist retatrutide for obesity—a phase 2 trial. N Engl J Med. 2023;389(6):514-526. doi:10.1056/NEJMoa2301972. PubMed.
5. Coskun T, Wu Q, Schloot NC, et al.
   
   Effects of retatrutide on body composition in people with type 2 diabetes: a substudy of a phase 2, double-blind, parallel-group, placebo-controlled, randomised trial. Lancet Diabetes Endocrinol. 2025;13(8):674-684. doi:10.1016/S2213-8587(25)00092-0. PubMed.
6. BioInfinity. Retatrutide (GLP3-R).
   
   Accessed October 9, 2026. Product source.
7. Wilding JPH, Batterham RL, Davies M, et al.
   
   Weight regain and cardiometabolic effects after withdrawal of semaglutide: the STEP 1 trial extension. Diabetes Obes Metab. 2022;24(8):1553-1564. doi:10.1111/dom.14725. PubMed.

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Author: Rob Miller

Rob Miller founded SupplementCritique.com over 7 years ago, and has been the chief editor ever since. He has a diploma in Advanced Dietary Supplements Advisor, and worked at GNC for 3 years. He KNOWS supplements, both inside and out. Rob currently resides in Jupiter, FL, with his wife of 4 years.  Learn more about him in his Bio here. Follow him on Twitter , Facebook, LinkedIn, or find him on Google +. View all posts by Rob Miller