THE PROBLEM with CAPSULES – DIGESTED TO NAM
This research published in 2018 confirms that most oral supplements of NMN and NR are digested to NAM in the GI tract or the liver.
At 50Mg/Kg of body weight, NO NR or NMN made it out of the liver intact.
Future pharmacological and nutraceutical efforts to boost NAD will need to take into account the minimal oral bioavailability of NR and NMN (R)
Unlike in cell culture where NR and NMN are readily incorporated into NAD, oral administration fails to deliver NR or NMN to tissues (R)
Interestingly, we found that neither compound was able to enter the circulation intact in substantial quantities when delivered orally (R)
That question is totally irrelevant if a molecule NEVER REACHES THE BLOODSTREAM.
This study used a small dose – 50 Mg/Kg of bodyweight (equivalent to 250 Mg for a 70 kg human), vs the 300-400 Mg/Kg commonly tested in other research. Perhaps higher dosages allow NAD+ precursors to make it past the Liver to other tissues.
It is clear that for Oral Supplements (Capsules), the bioavailability of any NAD+ precursor is very poor outside of the Liver.
SUBLINGUAL DELIVERY BYPASSES THE STOMACH AND LIVER
The absorption of the different molecules delivered through the sublingual route can be 3 to 10 times greater than oral route and is only surpassed by direct IV injection (r).
SUBLINGUAL CAN BE MORE BIOAVAILABLE THAN IP INJECTION !
With intraperitoneal injection, the primary route of absorption is via the mesenteric vessels, which drain into the portal vein and pass through the liver before reaching the bloodstream.
This means, IP avoids the GI tract, but is still sent directly to the Liver, where much of it is converted to NAD+. Elevated NAD+ in the liver is good, but its far better to reach the bloodstream with intact NMN.
Sublingual delivery is not filtered by the Liver and can reach systemic circulation intact, so can actually result in greater bioavailability that direct injection! Some examples are:
- A sublingual formulation of zol… exhibited a faster rate of absorption and higher drug exposure as compared to subcutaneous injection (r)
- sublingually administered epin… results in more rapid absorption and a higher peak plasma concentration compared to injected epin… .(r)
- 40mg of sublingually administered pir.. was found to be as effective as a 75 mg intramuscular injection of dicl… (r)
NAD+ METABOLISM IN HUMANS
NAD+ can be synthesized in humans from several different molecules (precursors), thru the De Novo and Salvage Pathways.
Nampt is the rate-limiting step in the salvage process (97).
As we age, Nampt enzyme activity is lower, resulting in less NAM recycling, less NAD+, more disease and aging (97,101).
SUBLINGUAL NMN AND NAD+ BYPASSES THE NAMPT BOTTLENECK
Restoring NAD+ in the Liver does not solve NAD+ deficiency throughout the body.
In the Liver, the CD38 enzyme metabolizes NAD+ to NAM, which is excreted to the rest of the body (r).
Sublingual delivery of NMN or NAD+ directly to the bloodstream bypasses the liver and the Nampt bottleneck that is the root cause of NAD+ deficiency in many tissues.
SHORT WINDOW FOR MAXIMUM AVAILABILITY
The chart at right is from the 2016 Mills study with mice given 300 mg/kg of bodyweight by oral gavage.
It clearly shows NMN is found in blood plasma within minutes, peaking at around 15 minutes. After that, NMN drops rapidly in blood, and appears as increased NAD+ in the liver.
Of course this is in Mice, and humans have a slower response, but we believe it is during the short time period when NMN is available in the bloodstream and can reach tissues throughout the body that the real benefits occur.
FREQUENCY – HOW OFTEN TO TAKE
Nearly all research on mice and humans using NR and NMN is focused on measuring NAD+ and the various metabolites in the Liver as it is the primary supplier of NAD+ throughout the body (r).
If elevating NAD+ in the liver is the goal, 1-2 larger dosages per day seem to be sufficient to achieve the maximum increase in liver NAD+ (r).
OUTSIDE THE LIVER
However, we believe supplying NMN directly to the bloodstream is more effective at increasing NAD+ not just in the Liver, but throughout the body.
Smaller, More Frequent dosages
Based on the short window that exogenous NMN is available in the bloodstream before being filtered out by the Liver, we believe smaller, more frequent dosages are likely more effective than 1-2 larger dosages.
Using this philosophy, many of our customers have been reporting more perceived benefit from more frequent intake, with many taking 6-12 times per day. We recommend taking 4-8 times per day, with at least 1 hour between dosages.
NOT EVERY DAY
We recommend taking 2-3 days off per week, ideally on days when you will be getting the least exercise. If you relax more on the weekend that is a good time to not take NMN.
CONCLUSION – WHAT WE RECOMMEND
Dr Sinclair takes 500 Mg of NMN CAPSULES per day and prescribes the same for his father, which is in line with dosages used in current and recently completed research on humans.
There is likely an upper limit on the effective dosage of NMN and NR capsules, which seems to be between 500 and 1,000 Mg per day.
We believe that sublingual delivery allows a much greater percentage of NMN to bypass the liver and reach other tissues.
When split between multiple smaller dosages, we believe 1,000-1,500 Mg a day can be taken before reaching the limit on maximum effectiveness.
We recommend taking 1 tablet, 4 to 8 times per day. Ideally, 1 upon waking, 1 immediately before and after exercise, and 1 before bed, with any others spread throughout the day.