Do NMN and NAD⁺ have different effects on the body?
Researchers use supplementation with NMN, NR and NAD⁺ to restore levels of NAD⁺ in mice, making them look and behave like they did when young and extending their lifespan.
Although they have similar effect in some organs, there may be differences in the effect they have in other tissues throughout the body.
NAD⁺ not effective in drinking water or in capsule form
The NAD⁺ molecule is twice as large as NR or NMN, and is totally degraded in the gastrointestinal tract, so researchers do not use NAD⁺ in drinking water of mice and it is not sold in capsule form for humans.
NAD⁺ in IV or IP injections
Research has been successful using NAD⁺ injections in mice.
In humans, clinics that provide NAD⁺ by IV are exploding in popularity, even though they charge over $1,000 a day and require the patient to be hooked up to a drip IV for 8 hours.
NMN and NR poor bioavailability in capsules
NMN and NR capsules are only partially digested in the stomach, but are almost totally metabolized in the liver and excreted as NAM (Liu, 2018).
Sublingual delivery solves the bioavailability problem
Molecules like NMN, NR and NAD⁺ that have low molecular weight and are hydrophilic can be absorbed through the capillaries under the tongue directly into the bloodstream. This is called Sublingual (under the tongue) delivery.
This may solve the bioavailability problem of capsules that get digested in the stomach, so NAD⁺ can be used instead of NAD⁺ precursors. It also may improve the effectiveness of NMN.
Why is there no sublingual NR?
Nicotinamide Riboside is not stable by itself, so Chromadex adds Chloride to make it stable.
ALL NR sold is actually Nicotinamide Riboside with CHLORIDE.
Unfortunately, the taste is not acceptable for sublingual use.
So NR is only available in capsule form, which much pass through the stomach and liver where it is metabolized to the less effective Nicotinamide (Liu, 2018) .
NAD+ crosses the blood brain barrier to increase NAD+ in the hypothalamus to increase energy expenditure and decrease hunger (more below).
Administration of LABELED NAD+ by IP and IV injection of just 1 mg/kg a day demonstrated that exogenous NAD+ crosses the blood brain barrier to enter the hypothalamus INTACT, reduces hunger and weight gain, and increases energy expenditure and fat burning in mice.
They also show that NR and NMN can not utilize the cd43 gap to cross the blood brain barrier.
This might explain why In humans, NAD+ clinics have found success treating addictions and other brain imbalances, but NR and NMN have not been used in similar fashion.
Importance of Hypothalamus for Energy Metabolism
The hypothalamus in particular has emerged as an integrating, superordinate master regulator of whole-body energy homeostasis.
In summary, the hypothalamus plays a key role in the regulation of appetite and food intake both in humans and rodents.
Hypothalamic inflammation impairs the effects of insulin and leptin, contributing not only to hyperphagia and obesity development but also to the associated dysregulation of glucose homeostasis.
Energy homeostasis is controlled mainly by neuronal circuits in the hypothalamus and brainstem.
The hypothalamus is the region of the brain that controls food intake and body weight.
Leptin and insulin signal the status of body energy stores to the hypothalamus.
These peripheral hormones influence their effects on energy homeostasis either by activating or inhibiting the activity of the orexigenic or anorexic peptides within the hypothalamus.
Hypothalamus as master aging clock
- Sublingual delivery may help NAD+ metabolites and precursors avoid digestion in the stomach and liver.
- NAD+ clinics use slow drip IV of NAD+ to avoid the stomach and liver. They are exploding in popularity, but the extreme cost and time required for treatment severely limit their application for the general public.
- Sublingual NAD+ delivery may help solve the bioavailability problem and mimics the slow drip delivery used successfully by NAD+ IV clinics.
- We believe the ability of NAD+ to increase metabolism through the hypothalamus has a great impact on the entire body.