Does the Ozempic Shot Make You Tired?

Last reviewed: June 10, 2026

Last updated: June 10, 2026

Written by: Jay Hastings, CEO of PlexusDx

Jay Hastings is the CEO of PlexusDx, a precision health company focused on genetic testing, blood biomarker insights, and personalized wellness recommendations. He has more than 20 years of experience across healthcare innovation, genomics, laboratory operations, healthcare investing, and strategic finance.

Medically reviewed by: Jayden Lee, PharmD, EMBA

Jayden Lee, PharmD, EMBA, is the PlexusDx Medical Science Liaison with a PharmD and MBA specializing in pharmacogenomics and clinical product development, with a proven ability to bridge the gap between genomic research and practical patient outcomes. Dr. Lee has more than 10 years of professional experience in clinical pharmacy, academia, and research.

Fatigue is listed in the Ozempic labeling, so it can. The Ozempic prescribing information names fatigue, along with dysgeusia and dizziness, among adverse reactions occurring at a frequency greater than 0.4% — meaning it is documented but uncommon relative to the reactions that dominate this drug's profile. For a sharper number, the Wegovy label, covering the same active ingredient at weight-management dosages, reports fatigue in 11% of treated adults versus 5% on placebo in the pooled weight-reduction trials. Both figures are worth knowing, because the placebo rate tells you as much as the treated rate does.

What the Two Labels Report

The Ozempic label groups fatigue with dysgeusia and dizziness as other adverse reactions with a frequency above 0.4% in its clinical trials. It does not give a precise percentage for fatigue, because the drug's most common adverse reactions, reported in at least 5% of patients, are nausea, vomiting, diarrhea, abdominal pain and constipation.

The Wegovy adverse reaction table is more granular and covers 2,116 adults on semaglutide 2.4 mg versus 1,261 on placebo. Fatigue, a category that includes asthenia, appears at 11% versus 5%. Nausea appears at 44% versus 16%, diarrhea 30% versus 16%, vomiting 24% versus 6% and constipation 24% versus 11%.

Reading the Placebo Column

Five percent of trial participants reported fatigue while receiving no active drug. That is not noise to be discarded; it is the base rate of fatigue in people enrolled in a structured weight-management program with a calorie deficit and an activity prescription.

The gap between arms — around six percentage points — is what the data attribute to the drug in that population. Most people who feel tired on this class are experiencing something that has more than one plausible cause, which is exactly why self-diagnosis is unreliable here.

Other Documented Contributors

Gastrointestinal reactions are frequent enough in this class that their downstream effects deserve mention. The labeling warns about acute kidney injury due to volume depletion and instructs monitoring of renal function in patients reporting adverse reactions that could lead to it. Persistent vomiting or diarrhea reducing intake is a mechanism, not a mystery.

Hypoglycemia is the other. The Ozempic label warns that concomitant use with an insulin secretagogue or insulin may increase the risk of hypoglycemia, including severe hypoglycemia, and reports that documented symptomatic hypoglycemia occurred in 17.3% and 24.4% of patients when Ozempic 0.5 mg and 1 mg respectively were coadministered with a sulfonylurea.

The Timing Question

Ozempic is administered once weekly, and the label states it may be given at any time of day, with or without meals, on the same day each week. Maximum concentration is reached one to three days post dose, and steady-state exposure is achieved following four to five weeks of once-weekly administration.

Those pharmacokinetics mean fatigue that appears in a consistent pattern relative to the injection is at least plausible as drug-related, while fatigue that has been constant since well before starting is probably not. That distinction is useful information for a prescriber and is worth noting before an appointment.

When It Warrants a Call

Fatigue that is persistent, worsening, or accompanied by other symptoms — lightheadedness, an inability to keep fluids down, severe or continuing abdominal pain, or changes in urination — is a reason to contact the prescriber rather than wait it out. Several of the conditions the labels warn about can present with fatigue as an early feature.

The general principle in the labeling is that adverse reactions capable of causing volume depletion warrant clinical attention. Nothing in that assessment can be delegated to an article, and it should not be.

The Compounded Caveat

If you are taking a compounded semaglutide preparation rather than Ozempic, there is no FDA-approved label or trial dataset specific to that product. The FDA does not review compounded drugs for safety, effectiveness or quality before marketing, and the figures above come from the approved products sharing the active moiety.

The FDA has also reported adverse events that may relate to compounded semaglutide or tirzepatide prescribed at doses beyond approved labeling, including more product per dose, more frequent dosing or faster escalation. New fatigue that coincides with a dosage change deserves a prompt conversation with the prescriber.

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Frequently Asked Questions

Is fatigue a listed side effect of Ozempic?

Yes. The Ozempic prescribing information names fatigue, along with dysgeusia and dizziness, among adverse reactions occurring at a frequency greater than 0.4% in its clinical trials. The label does not assign a precise percentage; its most common adverse reactions, reported in at least 5% of patients, are nausea, vomiting, diarrhea, abdominal pain and constipation.

How often does fatigue occur with semaglutide?

The Wegovy label, covering the same active ingredient at weight-management dosages, reports fatigue — a category including asthenia — in 11% of 2,116 treated adults versus 5% of 1,261 on placebo in the pooled weight-reduction trials. The roughly six percentage point difference between arms is what the data attribute to the drug in that population.

Could low blood sugar be causing the tiredness?

It is possible in some circumstances. The Ozempic label warns that concomitant use with an insulin secretagogue or insulin may increase the risk of hypoglycemia, including severe hypoglycemia, and reports documented symptomatic hypoglycemia in 17.3% and 24.4% of patients when Ozempic 0.5 mg and 1 mg respectively were coadministered with a sulfonylurea. That assessment requires a clinician.

Does the timing of the injection affect fatigue?

The label states Ozempic may be administered at any time of day, with or without meals, on the same day each week. Maximum concentration is reached one to three days post dose and steady state after four to five weeks of once-weekly administration. Fatigue occurring in a consistent pattern relative to the injection is worth describing to a prescriber, along with when it began.

When should tiredness prompt a call to the prescriber?

When it is persistent, worsening, or accompanied by lightheadedness, inability to keep fluids down, severe or continuing abdominal pain, or changes in urination. The labeling warns about acute kidney injury due to volume depletion and instructs monitoring of renal function in patients reporting adverse reactions that could lead to it. These distinctions require clinical assessment.

Medical and Editorial Standards

Medical review process: This article was reviewed for medical accuracy, scientific clarity, evidence alignment, and appropriate discussion of genetics, medications, supplements, biomarkers, and health-related claims.

Sources and evidence: PlexusDx educational content is developed using peer-reviewed research, clinical literature, reputable medical references, and, where applicable, public health or regulatory guidance.

Commercial transparency: PlexusDx offers genetic testing, blood biomarker testing, personalized supplement recommendations, and related precision wellness services. Product mentions are intended to help readers understand available options and should not be interpreted as medical advice.

Important disclaimer: PlexusDx educational content is for informational purposes only and should not be used as a substitute for professional medical advice, diagnosis, or treatment. Always consult a qualified healthcare provider before making decisions about medications, supplements, genetic testing, lab testing, or health-related care.