Myers cocktail, IV glutathione and NAD+. Bypassing the gut is not a shortcut past physiology; it removes the regulation that gut absorption provides.
The Myers cocktail (typically magnesium, calcium, B vitamins, and vitamin C delivered by IV) has a legitimate basis. Magnesium IV does relieve migraines. High-dose B12 IV can help in verified deficiency. That last phrase is doing a lot of work. The concern begins with the vehicle. Multi-dose vials used in most IV therapy settings require antimicrobial preservatives. The most common are benzyl alcohol and phenol. Benzyl alcohol is a central nervous system toxin, listed as a Proposition 65 reproductive toxicant, and has caused fatal gasping syndrome in neonates even at doses considered routine. Phenol is a systemic toxin, antiseptic at surface concentrations, harmful to liver and kidneys at systemic doses. Neither is disclosed to the person sitting in the IV chair. Neither is on the menu.
But the deeper problem is not only what is in the vial. It is what the IV bypasses. When you eat food containing B12, the gut regulates absorption based on available intrinsic factor and actual cellular need. When stores are sufficient, absorption falls. When stores are low, absorption rises. This regulation is physiological and automatic. An IV has no such mechanism. It delivers the full dose regardless of whether your cells needed it, were ready for it, or had anywhere to put it. The body's signaling systems (which govern how much of a nutrient enters circulation, how fast, and where it goes) are bypassed entirely. What the body would have absorbed gradually from food, in the context of cofactors, across hours of digestion, arrives as a bolus in minutes. There is no off switch. The surplus must be processed, stored, or excreted by organs that were not expecting a flood.
The body does not manage nutrients in isolation. Every mineral, vitamin, and cofactor exists in a dynamic equilibrium with dozens of others: competing for the same transporters, enzymes, and receptor sites. When you flood the bloodstream with a high-dose single nutrient by IV, you do not simply raise that nutrient's level. You shift the entire balance.
High-dose magnesium IV suppresses calcium, producing transient hypocalcemia, the same mechanism that causes the cardiac arrhythmia risk in chelation. High-dose B12 consumes folate cofactors and methyl donors faster than they can be replenished. High-dose vitamin C at IV concentrations drives copper oxidation and depletes copper enzyme activity, the very enzymatic activity needed for the anti-inflammatory pathways vitamin C is supposed to support. High-dose zinc (included in some formulations) blocks copper absorption at the gut level even though it is being delivered past the gut. Pushed magnesium competes with potassium for renal reabsorption: high urine magnesium pulls potassium with it, contributing to hypokalemia. High-dose glucose in IV solutions spikes insulin, driving potassium into cells and dropping serum potassium further.
The body was designed with a finely tuned mineral ratio system. The ratio of magnesium to calcium, zinc to copper, sodium to potassium, iron to ceruloplasmin. These ratios are as important as the absolute level of any individual nutrient. An IV that pushes one number in isolation moves every ratio that number participates in. The clinic is measuring none of them. Neither, in most cases, is the person ordering the drip.
Glass IV vials leach aluminum. Rubber stoppers used on multi-dose vials contain aluminum compounds. Studies on parenteral nutrition, IV feeding used in hospitals, have documented aluminum accumulation in bone, brain, and liver from what were considered safe delivery systems. The wellness IV setting uses the same vials. The person receiving weekly Myers cocktails is receiving a cumulative aluminum load that has never been studied in that context, through a delivery route that bypasses all of the body's aluminum filtration mechanisms. The gut filters a substantial portion of ingested aluminum. The IV does not give the gut the option.
Anaphylaxis is a documented risk of IV nutrient therapy, not theoretical, not rare. It has been reported following Myers cocktail infusions, high-dose IV vitamin C, and IV magnesium. The mechanism is not always allergy to the active nutrient. It is frequently a reaction to the preservatives, the excipients, the delivery vehicle, or the osmolarity of the solution flooding the bloodstream. Benzyl alcohol, polysorbate 80, and sulfite preservatives are all documented anaphylaxis triggers. The IV bypasses the gut's first-line immune surveillance. The mucosal immune system that would normally sample a substance gradually and mount a graduated response. What the gut would have filtered or modulated arrives all at once in the bloodstream, where the systemic immune system has no graduated option. It responds at full intensity or not at all.
For people with mast cell activation syndrome (MCAS): a condition that is far more prevalent than diagnosed, particularly in people with chronic fatigue, fibromyalgia, hypermobility, dysautonomia, and long COVID. IV nutrient therapies are a specific and serious risk. Mast cells are concentrated in connective tissue surrounding blood vessels. An IV bolus of a substance the mast cells have been sensitized to, or a novel antigen they react to unpredictably, triggers degranulation: the sudden release of histamine, tryptase, heparin, prostaglandins, and leukotrienes directly into the vascular environment. The response can range from flushing, hives, and hypotension to full anaphylactic cardiovascular collapse. People with MCAS often do not know they have it. They frequently have a history of "unusual reactions" to medications, supplements, foods, and fragrances. A history that is rarely taken seriously as a contraindication before an IV line is placed. The wellness IV clinic did not take a mast cell history. It does not have epinephrine drawn and ready. It has a drip chair and a menu.
The convergence of MCAS with the population seeking IV wellness therapies is not coincidental. People with chronic, unresolved, medically dismissed illness are the target market for IV wellness. They are also, disproportionately, the people whose immune systems are most sensitized, most reactive, and most likely to respond catastrophically to an intravenous antigen load that bypasses every layer of regulation the gut and lymphatic system would otherwise provide.
Sodium benzoate is used as a preservative in some IV solutions and many oral supplements taken alongside IV therapy. In the presence of ascorbic acid (vitamin C) and trace metals, sodium benzoate converts to benzene, a Group 1 IARC carcinogen with no safe threshold. This reaction is well documented in beverages and has been confirmed in vitro under physiological conditions. High-dose IV vitamin C in a formulation containing sodium benzoate creates this reaction directly in the bloodstream.
This is covered in detail in the Isolated Supplements tab. The short version: glutathione is the body's master antioxidant and also the primary mechanism by which cancer cells protect themselves from oxidative destruction. Elevated intracellular glutathione in cancer cells is a documented marker of chemotherapy resistance and metastatic potential, particularly in breast cancer. High-dose IV glutathione floods systemic circulation with the same protective shield that aggressive tumors use to survive. A person with undetected malignancy, which describes a meaningful portion of the wellness population, may be accelerating the process they are trying to prevent. The IV route is more bioavailable and faster-acting than oral supplementation, which makes this risk more acute, not less.
NAD+ (nicotinamide adenine dinucleotide) IV is marketed as cellular regeneration, anti-aging, neurological repair, and addiction recovery. NAD+ is genuinely important. It is a central coenzyme in mitochondrial energy production and DNA repair. The question is whether flooding the bloodstream with IV NAD+ does what is claimed. The answer, from the people receiving it, is that it is frequently agonizing. Side effects during infusion are not mild. They are severe enough that most clinics require the infusion to run over 4–8 hours, and even then, many patients cannot tolerate it at any speed without stopping.
The reported experience during IV NAD+ infusion includes: intense chest tightness and pressure indistinguishable from a cardiac event; nausea and vomiting; severe muscle cramping, particularly in the abdomen and legs; palpitations and a racing, irregular heartbeat; flushing and full-body heat; profound anxiety and sense of impending doom; lightheadedness and near-syncope; and disorientation. These are not rare outliers. They are common enough that IV NAD+ providers list them as standard expected effects and simply slow the drip rate in response. The body is signaling in every available language that it is not handling this gracefully. The clinic's response is to slow the rate, not to stop and ask why a wellness intervention produces a chest pain protocol.
There are no long-term randomized controlled trials of IV NAD+ in humans for any of the conditions it is marketed to treat. Beyond the infusion reactions, the long-term biological consequences are genuinely unknown. NAD+ is not a passive molecule. It is a central signaling substrate for sirtuins (longevity-associated enzymes), PARP enzymes (DNA repair), and CD38 (immune regulation). Flooding the system with supraphysiological IV NAD+ doses repeatedly disrupts all of these pathways simultaneously. Whether chronic supraphysiological NAD+ drives paradoxical cellular senescence, disrupts immune surveillance, or alters DNA repair fidelity over years has not been studied. The people paying $1,000 per session are the experiment.