MOTS-c user experiences: what users themselves report
Users’ own accounts, not research. The accounts are self-selected and prove neither that it works nor that it is safe.
This page does not list users’ doses or sellers, and no figure on it is a recommendation. Doses used in studies, with sources: MOTS-c dosage in studies.
In short
Of 76 people, 37 (49%) said MOTS-c brought some benefit and 43 (57%) some harm.
- An AI model read and classified 300 public Reddit posts one by one, following written instructions. Leaving out posts that looked like marketing, 77 were first-hand accounts, from 76 different people.
- Benefits mentioned most often: endurance or exercise performance (12, 16%), more energy (12, 16%) and fat or weight loss (9, 12%).
- Harms mentioned most often: injection site pain or reaction (14, 18%), allergic reaction, hives or rash (7, 9%) and fatigue (6, 8%). In addition, 14 (18%) described some other, rarer harm. People tend to post when something goes wrong, so this share does not tell how common harms are.
- In all, 43 people described how strong a harm was, and 5 of them described it as severe.
- The accounts cannot separate the substance from placebo or other causes. What the research shows: MOTS-c: what the research shows.
Where the accounts come from and how we read them
Sources: the Reddit forums r/Peptides (39 accounts), r/Biohackers (36) and r/Retatrutide (2), 30 Nov 2024 to 23 Sep 2026. The posts were retrieved from a public Reddit archive. From first-person posts about MOTS-c, 300 were picked at random, and every one was read.
Coding: for each account we recorded the route, reported benefits and harms, how strong a harm was, whether and why the person stopped, length of use and other substances used at the same time. We kept accounts that reported some effect, some harm, or no effect. Questions and plans were left out. A harm was recorded when the person reported it during use, even if the cause was uncertain. Several posts by one person count as one person. One person can mention several things, so the shares in the tables do not add up to 100.
Check: an AI model read and classified the posts following written instructions. A second, separate AI run classified a random tenth (30 posts) again without seeing the first classification. The main fields matched: 29/30 (97%). One post looked like marketing and is not in the figures.
Whose accounts these are: routes mentioned: injection 24, nasal spray 1; the others did not say. The figures describe the writers and are not a recommendation. The products were not verified, so we do not know what people actually took.
Did MOTS-c help? The overall picture
Of 76 people, 28 (37%) reported benefit only, 9 (12%) both benefit and harm, 34 (45%) harm only and 5 (7%) neither.
Stopping. 14 people (18%) said they stopped or paused: 11 because of harms and 3 because they noticed no effect or for another reason.
| Overall picture: benefit, harm or neither | People | Share |
|---|---|---|
| Benefit only | 28 | 37% |
| Both benefit and harm | 9 | 12% |
| Harm only | 34 | 45% |
| Neither benefit nor harm | 5 | 7% |
Most common reported benefits
Of 76 people. 37 (49%) mentioned some benefit; the table lists every benefit reported.
| Reported | People | Share |
|---|---|---|
| Endurance or exercise performance | 12 | 16% |
| More energy | 12 | 16% |
| Fat or weight loss | 9 | 12% |
| Focus | 4 | 5% |
| Mood | 3 | 4% |
| Recovery | 3 | 4% |
| Sleep | 2 | 3% |
| Other benefit | 12 | 16% |
Share = people / 76.
Most common reported harms
Of 76 people. 43 (57%) mentioned some harm; 4 said explicitly they had none.
| Reported | People | Share |
|---|---|---|
| Injection site pain or reaction | 14 | 18% |
| Allergic reaction, hives or rash | 7 | 9% |
| Fatigue | 6 | 8% |
| Palpitations or fast heart rate | 5 | 7% |
| Flushing or heat | 4 | 5% |
| Dizziness | 2 | 3% |
| Blood sugar swings | 2 | 3% |
| More hunger | 2 | 3% |
| Insomnia | 2 | 3% |
| Nausea | 1 | 1% |
| Other, rarer harm | 14 | 18% |
Share = people / 76.
How severe were the harms?
Of the 43 people who described how strong a harm was, 23 (53%) described it as mild, 15 (35%) as clearly bothersome and 5 (12%) as severe. The strength is the writer's own description, not a doctor's assessment.
| Strength of the harm as the writer described it | People | Share |
|---|---|---|
| Mild: minor and manageable | 23 | 53% |
| Clearly bothersome: several days, sleep or work affected | 15 | 35% |
| Severe: emergency visit, hospital or unable to function | 5 | 12% |
Harms known from research and regulators: What are the side effects of MOTS-c?
How long did people use MOTS-c?
49 of 76 people (64%) said how long they had been using it at the time of writing. Where one person wrote several posts, the longest stated time counts.
| Stated length of use | People | Share |
|---|---|---|
| Under a week | 14 | 29% |
| 1-4 weeks | 22 | 45% |
| 1-3 months | 9 | 18% |
| Over 3 months | 4 | 8% |
Many people post partway through, often in the first days or as soon as harms start, so short times are over-represented. The numbers describe the writers; they do not say how long it should be used.
Other substances at the same time
51 of 76 people (67%) used other substances at the same time. The most common: retatrutide (30), NAD+ (15) and tesamorelin (14). Then the account cannot tell which substance had the effect.
Allergic-type reactions
7 of 76 people (9%) described an allergic-type reaction such as hives or a rash, and 14 (18%) pain or a reaction at the injection site. 5 people described a harm as severe (an emergency visit, hospital, or being unable to function). That figure covers all harms, not only allergic-type reactions.
According to the FDA, products containing MOTS-c may carry a risk of immune reactions: What are the side effects of MOTS-c? The figure from the accounts only says what people wrote, not how common the reactions are.
About dosing
We do not repeat the amounts or ways of use people mention, and we give no dosing or how-to instructions. A safe dose is not known. Doses used in studies, with sources: MOTS-c dosage in studies. Legal status: Is MOTS-c legal in Finland?
What can be concluded?
Energy and endurance were the most common reported benefits, but many used other substances at the same time. Among harms, injection-site symptoms and allergic-type reactions stood out.
The accounts prove neither that it works nor that it is safe. The writers are self-selected, the product contents are unknown, many used several substances at once, and placebo effects can be large. The research and its evidence levels: MOTS-c: what the research shows.
Quotes
Short excerpts in the writers’ own words. Writers’ names and links are not shown. We picked quotes from every group: benefit, both benefit and harm, no effect, harms and people who stopped.
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"Fatigue is gone. A.m. cardio is a breeze and noon weights is no longer dreaded."
r/Biohackers, 2026-04, Route not stated. Added MOTS-c to retatrutide about a week before writing; the fatigue from retatrutide went away and training felt easier.
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"while I have noticed some fat loss, I’ve also noticed all my workouts have gottne much worse endurance wise."
r/Peptides, 2025-10, Route not stated, almost 3 weeks. Some fat loss, but running and rowing times got worse.
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"Most recently I’m doing MOTS-C for a month. Nothing."
r/Peptides, 2026-03, Route not stated. About a month of use with no noticeable effect, the same as with several other peptides.
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"Upon injecting - burn, itchy, welts around injection for 3 days."
r/Peptides, 2025-02, Injection under the skin, first use. An injection site reaction was the most often reported harm.
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"15 mins in felt flush and dizzy, insides of the ears started itching."
r/Biohackers, 2026-07, Injection, first small test shot. Allergic reaction: flushing, dizziness, itching, fast pulse and trouble swallowing; the writer went to the ER.
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"I stopped taking it last Friday because I noticed I was starting to get big welts UNDER my skin."
r/Biohackers, 2026-06, Injection under the skin, 2-3 weeks. A histamine reaction after each shot, then large itchy welts under the skin; stopped because of it.
Other summaries made with the same method: BPC-157 user experiences, NAD+ user experiences, NMN user experiences, SS-31 user experiences, Retatrutide user experiences, Tesamorelin user experiences, Epitalon user experiences and user experiences with collagen and skin peptides.
Content is general information about research, not medical advice. If you have symptoms, contact a healthcare professional.