Transiently Induced Immune Deficiency and Therapy

[nanna1]

  The following post describe an immune therapy that I designed and administered to myself. This therapy is patterned after immune therapies that have been studied for the treatment of cancers and viral diseases. It has been tailored to improve the typical experience of POIS sufferers based on the work of N. Jiang, et. al. (2015) and P. Haake et. al. (2004) as well as medical test posted to Medical Test Results and discussions (public and private) from POIScenter forum.

• Normal immune sexual response
• Aberrant Immune Suppression and Immune Tolerance
• Immune Suppression model of POIS
• Therapy Targets
• Possible solution: Immune Competence Therapy

[nanna1]

1. Normal immune sexual response:

  In the paper, "Effects of Sexual Arousal on Lymphocyte Subset Circulation and Cytokine Production in Man" they found that of the most common lymphocytes, natural killer (NK, CD56, CD57) cells experience the greatest increase in the blood circulation by sexual activity and appear to peak around the time of orgasm. While a small increase in (CD8) T cells was measured, (CD4) T cells and B cells do not change significantly during coital behavior.

"the orgasm induced a moderate but statistically significant transient elevation of the cytotoxic/suppressor T cell (CD3+CD8+) numbers (Fig. 2). In contrast, the absolute numbers of T cells (CD3+), T helper cells (CD3+CD4+), and B cells (CD3-CD20+) were not affected by sexual stimulation...the levels of LPS-induced proinflammatory cytokines (IL-6, TNF-alpha) remained unaffected by masturbation-induced orgasm...The effects of orgasm on peripheral lymphocyte subsets were restricted to NK cells and had minor or no effects on T or B cell subsets and showed no effects on (IL-6, TNF-alpha) cytokine production, indicating limited and selective effects of orgasm on immune system functions in parallel with its selective and short-lived neuroendocrine effects." -Effects of Sexual Arousal on Lymphocyte Subset Circulation and Cytokine Production in Man (P Haake, U Hartmann, et al., 2004)

  During sex, the immune system is enhanced because beta-endorphins block the immune suppression effects of adrenaline/noradrenaline. Beta-endorphin also stimulates the innate immune response to viruses and inhibits viral replication. See: Ref1, Ref2
For example:

"We found that beta-endorphin but not dynorphin could stimulate NK cell activity... beta-endorphin appears to be one of the signals that is induced in the brain at the CS recall step of the conditioned response to trigger the elevation of NK cell activity."
-Expression of the conditioned NK cell activity is beta-endorphin dependent

The activity of, NK cells are believed to be upregulated by endorphins, dopamine, serotonin and nitric oxide in the following way:

Ultimately, serotonin and nitric oxide participate in a complex sequence of immune signaling where by melatonin, IL-12, IL-2 and prolactin produce an expansion in the number and activity of NK cells.

  The most "successful" pathogens remain latent (hidden) in the body and selectively reactivate their replication whenever bodily fluids are being exchanged from person-to-person. Some sexually transmitted infections (STIs, STDs) trigger reactivation from the same neurotransmitters that trigger semen ejaculation (epinephrine and norepinephrine) (post1, post2, post3, post4). So the pathogen replication is syncronized to the exchange of bodily fluids (saliva, sweat, semen).
  The increase in NK cells during sex is needed to suppress these STDs and prevent the spread of infections during sexual fluid exchange. These immune cells are one of the bodies most efficient killers of pathogens (earning the name Natural Killer cells).   

[nanna1]

2. Immune Suppression and Immune Tolerance:

  The female genital tract is highly dense with immune cells that aggressively kill any thing with foreign DNA (including harmful bacteria, viruses and sperm). So semen contains a high density immune signalling molecules such as prostaglandins (prostate-gland-in), spermidine and spermine. These signalling molecules increase the likelihood that his sperm will fertilize her eggs by suppressing the immune system (including NK cells) in her genital/vaginal tract. Over time her immune system learns (through spermadine/spermine signalling) to tolerate the man's DNA and sperm without forming an immune response. This is called immune tolerance.

  However, if these immunosupressing molecules (PGE₂, spermidine, spermine, etc...) increase in other parts of the body during sexual activity, they could suppress the protective NK cell function and ultimately allow pathogens to reactivate. Certain viruses such as HSV-1, HSV-2, VZV and CMV encourage this scenerio by upregulating the COX-2 arachidonic acid enzyme in their latent host cells. So these viruses modify the cellular enzymes (i.e. COX) to make their own replication favorable.

  Note that PGE₂ induced upregulation of arginase leads to L-arginine and nitric oxide depletion. This is because arginase decreases the available pool of L-arginine for Nitric Oxide Synthase (NOS). As a result, high arginase levels are associated with epithelia and endothelial dysfuction.   The PGE₂ induced upregulation of IDO1 leads to the depletion of Tryptophan and serotonin. Decreases in serotonin leads to a decrease in melatonin (sleep quality) and N-acetylserotonin (antidepressant). While increases in kynurenine contribute to immune tolerance.

  When NK cell function is suppressed, it can lead to an increase in inflammatory chemokines and a dependence on CD8 T cells to perform the anti-viral (or anti-bacterial) functions of NK cells. Relative to NK cells, CD8 T cells have a slower pathogen-killing response which delays the clearance of the pathogen. (click image to get full size)

Figure 4 from: "Deciphering the role of DC subsets in MCMV infection to better understand immune protection against viral infections"

  A suppression of NK cells (low NK) causes inflammatory pathogen-based disease (CD8 w/o NK), while a healthy NK response (NK) prevents symptoms (CD8 w NK: grey):

Abstract Figure from: "Human Natural Killer Cells Prevent Infectious Mononucleosis Features by Targeting Lytic Epstein-Barr Virus Infection"

[nanna1]

3. Immune Suppression/Immune Tolerance model of POIS

  Many theories of POIS center around an assumption that the immune cells are too active and need to be suppressed or stabilized. Here, I present the exact opposite theory, namely that cytotoxic innate immune cells, such as natural killer (NK, CD56 or CD57) cells are not active enough and need to be increased. NK cells are protective against the reactivation of latent infection. It is the absence of a competent innate (NK) immune response that causes increased inflammatory chemokine release due to uncontrolled pathogen replication. In other words, POISers experience a temporary immuno-compromised state triggered by certain neurohormones (adrenaline, PGE₂, etc...) of the sexual response cycle.

  In the paper "Immunophenotypical Characterization of a Brazilian POIS patient", the POIS patient was found to be deficient in cytotoxic natural killer (NK) cells and B lymphocyte cells, and an over expression of monocytes. The aurthors of this paper also note that:
"Some studies have shown a decrease of NK cell percentage in association with a reduction of activity of these cells in peripheral blood of patients with depression. Other mental disorders such as mental stress, autism and obsessive-compulsive disorder have also been reported to present lower NK cell activity."

  The deficiency in Natural Killers indicates that immune suppression could be preventing this patient from forming a competent immune response. The deficiency in B cells may indicate that immune tolerance is preventing humoral immunity from correcting the problem associated with POIS. Without a competent humoral/memory immunity, the immune system treats the reactivation of latent infections as if it is a new/acute infection. One of the main signaling roles of spermine and kynurenine is to induce immune tolerance to foreign substances and DNA. This immune tolerance can inhibit the formation of cytotoxic T cell memory of pathogens and prevent a competent humoral response.
 
  Since, most POISers recover from POIS in the 5 to 7 day range. The time kinetics of NK, T, B cells seems to suggest that, in the absence of an immunocompetent NK response, POIS recovery is correlated with the time-dependent expansion of non-memory CD8+ T cells.

Figure 7 from: Global Transcriptome Analysis in Influenza-Infected Mouse Lungs Reveals the Kinetics of Innate and Adaptive Host Immune Responses

 
  This time-dependent increase in CD8 T cells occurs during sleep (How Sleep Fights Infection: Snoozing Makes Killer Immune Cells More Sticky). So, the sooner sleep occurs following orgasm, the sooner CD8 T cells can start replacing the function of NK cells in the immune response. Moreover, sleep deprivation has been shown to suppress NK cells in humans (Ref1, Ref2, Ref3). So good sleep is vital for immune function and recovery from POIS.

  So this immune suppression model predicts that normal (non-POIS) people rely upon a transient increase in NK cell activity to suppress latent infections, while POISers rely upon the slower CD8 T cell increase to control those same latent infections. This means that POISers should experience a (days-long) elevation in chemokines due to the delay in time that it takes the adaptive (non-memory) T cells to respond. Transient PGE₂ release induces the arginase-1 and IDO1 mediated suppression of innate cells (namely Natural Killers).

[nanna1]

4. Therapy Targets

Adenylyl cyclase
  Adenylyl cyclase is an enzyme that produces cyclic AMP (cAMP) from the basic energy substrate ATP. Norepinephrine (norepinephrine) and epinephrine (adrenaline) bind to beta-adrenergic receptors to activate adenylyl cyclase. Prostaglandin E2 (PGE₂) also activates adenylyl cyclase. This adenylyl cyclase activation causes an increase in cAMP. Herpes viruses reactivate when rising cAMP levels induce arginase activity in infected cells (see Ideas on Herpes Induced POIS). Cyclic AMP stimulates the up-regulation of arginase-1, while cyclic GMP does not stimulate arginase-1. There are direct and indirect inhibitors of adenylyl cyclase. Flush niacin, acetylcholine, dopamine and beta-endorphins inhibit adenylyl cyclase indirectly through G_i coupled protein receptors.

From: Cardiac Muscle Contraction

"The addition of exogenous nicotinamide adenine dinucleotide (NAD) to isolated rat fat cells at concentrations between 1 and 10 μmol markedly inhibited the rise in cyclic AMP accumulation due to norepinephrine...NMN was as potent as nicotinamide while nicotinic acid (flush niacin) was 100- to 500fold more effective than either compound as an inhibitor of cyclic AMP accumulation."
-Effect of NAD, nicotinamide and nicotinic acid on cyclic AMP accumulation by fat cells

• Caffeine directly inhibits adenylyl cyclase by competitive binding to the location (active site) where ATP interacts.
• Nicotinic acid (flush-niacin) inhibits adenylyl cyclase through the GPR109A receptor (Ref1)
• Dopamine inhibits adenylyl cyclase through the D2 dopamine receptor
• Endorphins inhibits adenylyl cyclase through the opioid receptors
• acetylcholine inhibits adenylyl cyclase through the (M2, M4) Muscarinic acetylcholine receptor

  Not every cell-type expresses these receptors and the corresponding neurohormones are only effective in localized portions of the body expressing these receptors. So an infected cell that does not express the opioid receptors will not be affected by beta-endorphin. While reactivation of infections in cells expressing these receptors may be suppress by beta-endorphin. However, the inhibition of adenylyl cyclase by caffeine is direct and does not depend on a G_i based receptor. So caffeine can act more universally across all cell types to block cyclic AMP production from beta-adrenergic and prostaglandin signalling.
  N Jiang suggested that a lack of endorphin signaling is a necessary feature of POIS manifestation. The endorphin receptors are adenylyl cyclase inhibitors.

Arginase
  Arginase produces the polyamines spermidine and spermine from L-arginine. Spermine suppresses the immune system and prevents immune cells from killing pathogens. Spermine also increases the rate that viral DNA can be replicated. Some viruses (like herpes) chronically up-regulate arginase through COX-2 and other genetic signaling (Ref1, Ref2).
"Many viruses have been shown to require polyamines for one or more aspects of their replication cycle, including DNA and RNA polymerization, nucleic acid packaging, and protein synthesis...Inhibition of polyamine synthesis with difluoromethylornithine (DFMO) results in a block of both HSV and HCMV replication." -Polyamines and Their Role in Virus Infection

Arginase also disrupts endothelial (blood vessel) barrier function:
"...Putrescine, spermidine and spermine, given individually, were found to disrupt Blood Brain Barrier (BBB) integrity within 15 min of i.c.v. administration...When injected into the carotid artery, rapid increase in BBB permeability was found 1 min after putrescine and spermidine..." -Polyamines induce blood-brain barrier disruption and edema formation in the rat (1996)
Arginase activity produces urea as a waste product so urea in the blood and may be a relevant biomarker of POIS.

cyclooxygenase-2 (COX-2)
  COX activity can increase protaglandin E2 (PGE₂) production. PGE₂ activates adenylyl cyclase leading to cyclic AMP increases. This process then induces immune suppression of NK and T (CD8) cells. Inhibiting COX and PGE₂ activity has be shown to increase NK cell numbers and activity (Ref1, Ref2, Ref3). It has also been shown that inhibiting COX has the effect of increasing beta-endorphin stimulating activity.

[nanna1]

5. Possible solution: Immune Competence Therapy

  The purpose of this therapy is to boost the immune system by increasing the cytotoxic activity of (neutrophils, lymphocytes and monocyte derived cells). The goal is to produce long-term improvements in the health by promoting increased immune activity (i.e. immune competence). This therapy is not focused on symptom reduction. Symptoms related to immune activation may both increase and decrease for short periods of time depending on the nature and location of pathogenic infections in the body. Once immune competence is established, this therapy should no longer be needed to sustain lasting improvements in health. If you are likely to quite the therapy as soon as symptoms of immune activation occur, this is not the therapy or treatment for you.

I. prevent transient immune suppression (prepack, 90min prior)
caffeine (150mg)
citrulline malate or citrulline nitrate (3g)
N-acetyl-tyrosine (200mg)
theanine (300mg)

II. immune activation stack (cycle - 6 days on, 4 days off, for ~5 months or until symptom remission)
**Warning: This therapy is designed to increase the total number of white blood cells and may (or should) increase the occurrence of some illness symptoms over a short-term period of time. The increased feeling of illness may last for several weeks. Cycling off the stack can reduce feelings of illness and improve immune response to the stack. However, fatigue, irritability and brain-fog are not expected to result from this therapy.**

Immuno Complex^(R) by Quality of Life^(R) (source 1, source 2):
(15 - 20 min before each meal / three times daily, requires food)

• active hexose correlated compounds (AHCC)
• zinc methionine
• copper oxide
• vitamin C (liposomal)
• vitamin D3
• Andrographis

beta-glucan (1g)
copper gluconate (2mg, empty stomach)

III. Broad Spectrum Pathogen load reduction
**This is designed to kill pathogens in the body without needing to know which pathogenic infections are present.**
Intravenous ascorbate (vitamin C drip 5g, repeated three consecutive days)
copper gluconate (2mg repeated three consecutive days, >3hrs prior to IV ascorbate)

IV. Epithelial barrier repair
folate (< 200mcg, every other day)
Liposomal vitamin C (1g, twice daily)

Notes:
  This therapy is not the exact therapy that I did because I was experimenting with a lot of stuff and I'm sure most of it did not have any lasting benefit to my POIS. The Immune Competence Therapy shown above is basically the lessons learned and what I would do if I had to do it all over from the beginning. (post1, post2). I have taken all of these supplements during my recovery from POIS.
  When stimulating the innate immune system (NK cells, neutrophils, etc...), these cell do not differentiate between infections that affect POIS and infections that do not affect POIS. A competent immune system will attempt to clear all pathogens in the body, not just pathogens which make POIS worse. This should be kept in mind if you experience signs of temporary immune activation in areas of the body which are not associated with your typical POIS symptoms.
prevent transient immune suppression:
  I currently believe that adenylyl cyclase activation is THE essential step to triggering POIS in infected sympathetic neurons. Adenylyl cyclase is activated by PGE₂, epinephrine and norepinephrine. Adenylyl cyclase is deactivated (inhibited) by dopamine D2 and opioid (endorphin) receptors (post). Caffeine is a natural adenylate cyclase inhibitor and an arginase-1 suppressor (post). However, caffeine also has many other pharmacological targets such as PDEs, xanthine oxidase and adenosine receptors. So caffeine should be timed ~90min prior to orgasm to avoid side-effects from other targets. Theanine has been shown to enhance NK cell and T cell killing function and improve the outcomes of various infection and cancer related disease (Ref). Theanine also prevents caffeine jitters.
  Citrulline malate should only be taken with an arginase inhibitor. Arginine is not a replacement for cirtulline. Without an arginase inhibitor, L-Arginine supplements could make POIS worse due to spermine production.
  Indomethacin is know to increase NK cell number and activity by inhibiting prostaglandin induced immune suppression (Ref1, Ref2, Ref3). Indomethacin has antiviral, antibacterial and anticancer properties due to this increase in NK cells. Indomethacin (with prepack, 50mg, 2.5hrs, only for the first two weeks) can be used as a quick immune stimulant to speed up results. If you take indomethacin, you should also take the antioxidants selenium and vitamin C (i.e. selenmethionine - 200 micrograms and ascobate-vitC - 500mg).
The research indicates that antioxidants like selenomethionine and vitamin C detoxify indomethacin (Ref1, Ref2, Ref3, Ref4).

The below figure shows the dose timing for pre-packs. t_start is when the dosing starts. t_max is ideally when sexual activity should begin. t_1/2 is the (half-life) window.


immune activation stack:
  Immuno Complex^(R) by Quality of Life^(R) is one supplement containing AHCC, zinc, copper, vitamin C, vitamin D3 and andrographis. AHCC stimulates NK cells and dendritic cells (Ref1, Ref2), while beta-glucan stimulates neutrophils and B lymphocytes (Ref3, Ref4).
  Vitamin C and vitamin D3 are absolutely required for health immune function.
  Copper has a strong antimicrobial and antiviral effect (Ref1). When taking copper, there is a small possibility of a Jarisch-Herxheimer reaction due to intestinal infections dying rapidly.
Epithelial barrier repair:
  The epithelial cell barriers surround every organ in the body and perform a quarantine role of preventing infections (and toxins) from spreading from one organ to the next. When experiencing chronic infection, the epithelial layers can be damaged by the pathogen (or the related inflammation), allowing the pathogen to spread. The spreading pathogen can then cause problems in new parts of the body. For example, a pathogen in the brain can damage the blood brain barrier (BBB endothelium). This allows the pathogen to leave the brain, travel through the blood and damage the epithelial cells of the intestines or the heart. Even after the pathogen is contained and/or removed from the body, the lingering damage to the organs can still cause problems (symptoms) from incomplete healing. Vitamin C and B9 work together with the immune cells to promote wound healing. Vitamin C stimulates collagen production, and vitamin B9 (folate) promotes DNA methylation. The white blood cells clear out the damaged cells by inducing autophagy, apoptosis and phagocytosis. These immune cells also release the proper growth factors to restore new epithelial cells to the damaged barrier.

[Quantum]

Hi nanna1,

my use of IDO and TDO inhibitors to prevent the up-regulating of kynurenine formation is along the same lines as your current hypothesis.  I focused more on the excessive formation of toxic kynurenine products and on tryptophan depletion for serotonin biosynthesis, but both approaches are additives rather than exclusive.  You also add the arginase 1/spermidin branch, too.

I totally agree that POIS would be more a immune "malfunction" than an over-active immune system.

[Nas]

Possible Solutions
*under construction*
COX inhibitor indomethacin, gallic acid
arginine prodrug: citrulline malate
arginase inhibitors: caffeine, gallic acid..

Tried all of these and non of them did anything.

[Muon]

Found this interesting and will dump it here: IDO: a double-edged sword for TH1/TH2 regulation

''Thus, IDO-activated Treg cells will subsequently suppress antigen-induced TH cell responses in a ?time delayed manner?. IDO-induced Treg cells may therefore contribute to the negative-feedback suppression of T cell responses. But the difference from IDO-directly suppressive role on T cells is that Treg cells inhibit both TH1 and TH2 type immune responses. In addition to inhibition of specific TH1 and TH2 responses, IDO-induced Treg may also mediate bystander suppression of cellular immune responses to ?the third party antigens?

My Th1 and Th2 cytokines seem to drop down after ejaculation if you look at the second time I measured them. There is no Th1/Th2 reciprocal cytokine release noticeable. Tregs can inhibit both responses via IDO.

Some other notes:

Stress can induce similar symptoms in me as POIS and aggravates POIS. Stress hormones act on TDO. My levels of cytokines IL-1, IL-6, TNF-alpha stay normal during POIS, these act on IDO instead of TDO.

[nanna1]

Found this interesting and will dump it here: IDO: a double-edged sword for TH1/TH2 regulation

''Thus, IDO-activated Treg cells will subsequently suppress antigen-induced TH cell responses in a 'time delayed manner'. IDO-induced Treg cells may therefore contribute to the negative-feedback suppression of T cell responses..."

I would agree that Treg and myeloid-derived suppressor cells (MDSC) mediate much of the immune suppression caused by spermine and kynurenine!

[FernandoPOIS]

Possible Solutions
*under construction*
COX inhibitor indomethacin, gallic acid
arginine prodrug: citrulline malate
arginase inhibitors: caffeine, gallic acid..

Tried all of these and non of them did anything.

In this line of reasoning, as your case is an inflammation in a smooth tissue (urethra) I believe that corticosteroids should work.

[Nas]

I don't think my urethra issues are related to POIS Fernando, because it can still bother me when I'm out of POIS. Also the last test I did showed normal mucus level in the urethra even though I still had slight burning. It's probably something unrelated.

[FernandoPOIS]

POIS will stay with you as long as you have any signs of inflammation. And there are other factors that will remind your immune system of this trauma: Low dopamine and serotonin. Unfortunately (my opinion).

[nebraska]

hi nanna1, i could say i also noticed correlation between POIS condition and pre-workout packs
I have never attached importance but after your post im looking for consistency of those mixes and the most powerful ingridients are citrulline malate 8g and 320mg of caffeine.
so, it was about 30-40% relief.

But, just wanna add some comment:
-My POIS has developed slowly, it took 3 days to revocer on the start 5 years ago, 7-10 day 2 years ago but now it never ends, just becoming stronger after powerful stimulation or eujaculation
how can you include that fact to your theory about CD8+ T cells expansion?
-i also have only cognitive symptoms but their power is really frightful, its so much brainfog and cognitive impairment all the time so i cant really contact people cause of that.
-i have unidentified rheuamothoid arhtritis but i havenot any markers of that  except CRP so my hips and knees are a little bit inflamed all the time but it started 2 years before POIS

hello worldwide sufferers from Russia

[FernandoPOIS]

Nebraska

I believe you will benefit from taking a long-term anti-inflammatory treatment and during this period stay in celibacy as long as you can.

[FernandoPOIS]

Forgive me for the pessimism, but all reasonings lead the same way:

Treat the cause of the inflammation. As this process is difficult, we end up falling into the same treatment that is the use of anti inflammatory drugs. And there's the fact that mental stress, low dopamine, and low serotonin are potential enhancers.
We know that prolonged use of prostaglandin and histamine inhibitors is risky. This vicious cycle seems to lead to the conclusion that POIS is a consequence rather than the cause and if it does not treat the cause there will be no cure.

[Muon]

-i have unidentified rheuamothoid arhtritis but i havenot any markers of that  except CRP so my hips and knees are a little bit inflamed all the time but it started 2 years before POIS.

Enhanced interferon gamma response contributes to disease remission in Rheumatoid Arthritis.

Interferon Gamma Suppresses Collagen-Induced Arthritis by Regulation of Th17 through the Induction of Indoleamine-2,3-Deoxygenase

Mechanisms of Disease: the link between RANKL and arthritic bone disease

''RANKL, through its ability to stimulate osteoclast formation and activity, is a critical mediator of bone resorption and overall bone density. Overproduction of RANKL is implicated in a variety of degenerative bone diseases, such as rheumatoid arthritis and psoriatic arthritis.''
https://en.wikipedia.org/wiki/RANKL#Clinical_significance

[nebraska]

update:
i have some meds that make me feel better and have some make me feel worse

none of antiflammatory drugs have effect on my POIS, for me its 100% no correlation
my arthritis and POIS are not correlated in symptoms. i can ejuaculate 50 times in a day but my inflammatin willnot get worse. just cognitive impairment
i believe somewhere fundamentally that things are related but not through stuff that can be depleted by NSAID and oters antiinflammatory

[Hopeoneday]

Many theories of POIS center around an assumption that the immune cells are too active and need to be suppressed. Here, I present the EXACT OPOSITE THEORY,

Well, me also suspecting this a long time ago, i would like to know-
is it in question supressed imune system, i can feel that it is.
But is this to all poisers???

https://poiscenter.com/forums/index.php?topic=2136.msg27037#msg27037

https://poiscenter.com/forums/index.php?topic=3098.msg31025#msg31025

https://poiscenter.com/forums/index.php?topic=2683.msg23835#msg23835

https://poiscenter.com/forums/index.php?topic=2695.msg26010#msg26010

I did read that one man on nackedscientists tryed imunosuppresants to test
this theory and didnt work:
https://www.thenakedscientists.com/forum/index.php?topic=6576.16680 and some of them ended crached after.

[nanna1]

...the most powerful ingridients are citrulline malate 8g and 320mg of caffeine.
so, it was about 30-40% relief.

Hi nebraska,

I would not take more than 130mg of caffeine in any one day. Also, it may be good to stay under 4g of citrulline. The 320mg of caffeine could be a problem a person who has pre-existing heart problems and lead to jitters. Too much citrulline could lead to nitrogen imbalance.