Adrian Crook Quit Retatrutide After 6 Months: What He Learned

This review checks the retrieved video transcript against clinical evidence. Crook's account can identify questions worth investigating, but it cannot confirm what his product contained or establish that retatrutide caused a particular symptom. His dosing, tapering and storage suggestions are personal practices, not validated treatment instructions.

His Starting Point and Dosing

"I started Retatrutide back on March 1st"

0:41

Crook started at 200 lbs, 5'10", roughly 19% body fat. He describes the following self-selected dosing:

"I started doing every other day, 0.33 milligrams. So about a milligram a week roughly. And I noticed it right away. Certainly within 24 hours, I noticed the appetite suppression."

— Adrian Crook

Weight Loss: 25 Pounds in 6–8 Weeks

"Within 6 to 7 weeks I had lost 25 pounds"

1:31

Crook reports losing 25 lbs in approximately 6–8 weeks at roughly 1mg per week:

"Probably within 6 to 7 weeks at the most 8 weeks I had lost 25 lbs. I'm not someone who enjoys eating at the best of times... I really leaned into the lack of appetite. And way too much. Obviously, that amount of weight loss in that short of time is not really healthy and it definitely ate into my muscle mass."

— Adrian Crook

He eventually stabilized around 175–176 lbs — a total loss of roughly 25 lbs from his 200 lb starting weight. That is a 12.5% reduction over 6 months.

The comparison with trials has limits. His reported result occurred over a different period, at changing doses, with self-directed eating and exercise. Phase 2 means of 8.7% at 1 mg and 17.1% at pooled 4 mg over 48 weeks describe study groups, not a benchmark for one person or an unregulated product.

Craving Elimination: Cigars and Alcohol

"My cigar habit went to zero"

3:09

One of Crook's most interesting observations was the elimination of non-food cravings:

"My cigar habit went to zero as well. I don't think this is a fluke. Those sort of dopaminergic loops... reta really short-circuits that across the board. So it's not just food or sweets — it can be smoking cigars in my case, it can be alcohol consumption."

— Adrian Crook

His account does not establish that retatrutide treats nicotine or alcohol dependence. It also cannot identify a dopamine mechanism. Evidence about another GLP-1 medicine should not be treated as proof of the same effect with retatrutide.

Reported DXA Lean-Mass Loss

"I had lost like 10 pounds of muscle"

4:59

Crook says he compared two DXA scans taken a year apart:

"I had a DEXA scan in the summer, and the last DEXA scan I had was the summer before, and I had lost like 10 pounds of muscle in that time. Pretty horrifying."

— Adrian Crook

He attributes this partly to retatrutide-induced undereating and partly to a shoulder injury that prevented upper body training for two months. His suggestion that retatrutide accounted for about half is his own estimate; the scans cannot separate the effects of medication, food intake, injury and training. DXA lean mass is not a direct measurement of skeletal muscle alone.

The Phase 2 body-composition substudy in people with type 2 diabetes found loss of both fat and lean mass. It did not test Crook's regimen or establish why his scans changed. See the study limitations before applying group results to an individual.

PPI Use and a Reported Digestive Episode

"The combinatorial effect of the two"

6:19

Crook describes a severe digestive episode that he attributes to combining the medicines:

"Because the PPI slows your stomach acid production and because rea slows gastric emptying, the combinatorial effect of the two meant that I woke up the next day and nothing was moving and it felt horrible and everything just came up the other way."

— Adrian Crook

He later stopped the PPI after viewer advice and used an apple-cider-vinegar mixture. His account does not establish that vinegar treats reflux or that stopping a prescribed PPI is appropriate. Discuss severe digestive symptoms and medication changes with a clinician rather than following the video's explanation or remedy.

Half-Life and Tapering

Crook references retatrutide's half-life multiple times:

"If you look at the 6 day half-life of retatrutide... you can see that when you drop under that sort of average, you can feel it quite frankly — your appetite spikes up."

— Adrian Crook

The approximately six-day half-life agrees with early pharmacokinetic research. It does not establish an appetite threshold, a precise date when all effects stop, or a safe injection interval.

Crook describes tapering, but the video is not evidence that his taper prevents appetite return or weight regain. There is no approved retatrutide discontinuation schedule.

Frequently Asked Questions

Sources

• Crook, A. (2025). "I Quit Retatrutide: My Final Verdict After 6 Months." YouTube. Watch on YouTube
• Jastreboff, A.M., et al. (2023). Triple-Hormone-Receptor Agonist Retatrutide for Obesity — A Phase 2 Trial. New England Journal of Medicine. DOI: 10.1056/NEJMoa2301972
• Effects of retatrutide on body composition in people with type 2 diabetes. The Lancet Diabetes & Endocrinology (2025).
• Coskun, T., et al. Early retatrutide pharmacology and pharmacokinetics. Cell Metabolism (2022).
• FDA. Concerns with unapproved GLP-1 drugs.