Fatigue, low energy and brain fog
Persistent tiredness deserves a look at what is behind it before it is treated. Where a deficiency is the driver, intravenous and intramuscular delivery bypass the variability of gut absorption.
Persistent fatigue is a symptom, not a diagnosis, and the most important thing about it is what sits behind it. Genuine causes range widely, including iron deficiency, thyroid dysfunction, diabetes, sleep apnoea, depression, chronic infection and medication effects, and a number of them are serious and treatable. Any responsible approach begins by asking whether the tiredness has been investigated, because an infusion given to someone with undiagnosed anaemia or hypothyroidism treats nothing and delays the diagnosis that would have helped. Where investigation has been done and a specific deficiency identified, the rationale for intravenous or intramuscular delivery is a real one: oral absorption is variable and, for B12 in particular, depends on intrinsic factor and gut integrity that many people lack, so bypassing the gut delivers a predictable dose. What that does not mean is that infusions are a general treatment for tiredness in people whose bloods are normal. The evidence for vitamin infusions in the absence of deficiency is weak, and the honest position is that they correct what is missing rather than add function to a system that already has enough.
How we treat it
Consultation comes first, and where fatigue has not been medically investigated, that investigation is the recommendation rather than an infusion. Where a deficiency has been identified, intravenous or intramuscular repletion is a reasonable and often effective route, particularly where oral supplementation has failed or absorption is impaired, and B12 by injection is the clearest example. Where bloods are normal, that is said plainly, and the discussion becomes one about sleep, stress and load rather than about drips. NAD+ therapy is offered in the context of energy metabolism and cellular repair, and it is described honestly: the mechanistic rationale is interesting, the clinical evidence base in humans is still developing, and it is not a substitute for diagnosing a treatable cause. Every infusion is prescribed and supervised by a clinician, dosed to the individual and administered in the clinic. None of it is a menu item selected without assessment.
Medically reviewed by Dr. Sherwin Hariri, MD, Medical Director & Chief Longevity Physician. Last reviewed August 2026.
This page is for information only and is not medical advice. Suitability for any treatment is determined at consultation.
Common questions
Will an IV drip fix my tiredness?
If a specific deficiency is driving it, correcting that deficiency often helps considerably. If your bloods are normal, an infusion is unlikely to be the answer, and we will say so. Fatigue with normal investigations usually points to sleep, stress or mood, and those need addressing directly rather than infusing around.
Do I need blood tests first?
In most cases yes, and it is in your interest. Treating fatigue without knowing whether iron, B12, vitamin D or thyroid function is abnormal means guessing, and it risks masking a condition that needs proper medical management. Where recent results exist, they can be reviewed rather than repeated.
Why injections rather than tablets?
Oral absorption is variable and can be poor, particularly for B12, which depends on intrinsic factor and an intact gut. Injection and infusion bypass that entirely and deliver a known dose. Where oral supplementation has been taken diligently without improvement, poor absorption is a common explanation.
What is NAD+ therapy and does it work?
NAD+ is a coenzyme central to cellular energy metabolism, and levels decline with age. The mechanistic rationale is sound and patient-reported outcomes are often positive, but human clinical evidence is still developing and we describe it on that basis. It is not a replacement for investigating a treatable cause of fatigue.
Other concerns
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