you mean mg of melatonin, you will not feel well with 600g… LOL. I am overweight and my lowest heart rate is 46. But everyone is different.
@Beth With age, body makes less melatonin, which I understand, and to take some melatonin to replace what’s lacking makes sense to me. However, taking anything in great excess makes that lacking chemical a strong medication, the mechanism of action of which is not fully understood as I read about it. So, I asked ChatGPT about possible complications of taking mega doses of Melatonin.
Taking mega doses of melatonin (far beyond the commonly recommended 0.5–5 mg range) on a regular basis can lead to a variety of short- and long-term complications, even though melatonin is generally considered safe in small doses for short-term use. Here’s a breakdown of potential complications:
1. Hormonal Disruption
Melatonin is a hormone, and taking large doses regularly can interfere with your body’s natural hormonal rhythms. This might affect:
- Reproductive hormones, potentially impacting fertility (especially in women).
- Puberty onset in adolescents.
- Menstrual cycle irregularities.
2. Sleep-Wake Cycle Disruption
Ironically, too much melatonin can throw off your circadian rhythm:
- You may start to feel groggy during the day and wide awake at night.
- Over time, your natural melatonin production could downregulate, making sleep harder without the supplement.
3. Mood and Cognitive Effects
Excess melatonin might contribute to:
- Depression or low mood.
- Brain fog or difficulty concentrating.
- Increased daytime drowsiness or sluggishness.
4. Drug Interactions & Health Risks
High doses of melatonin can interact with:
- Blood thinners (e.g., warfarin): increased bleeding risk.
- Immunosuppressants: may interfere with immune function.
- Diabetes medications: may affect blood sugar control.
- Seizure medications: can increase risk of seizures in some people.
5. Headaches, Dizziness, and Nausea
Common side effects at higher doses:
- Headaches
- Dizziness
- Nausea
- Vivid dreams or nightmares
6. Tolerance and Dependency
While melatonin isn’t typically considered addictive, using large doses frequently can lead to:
- Psychological dependence (“I can’t sleep without it”).
- Reduced effectiveness over time (needing more to get the same effect).
It was enough for me not to take mega doses or even take it consistently every night. Logically, I cannot agree with taking anything in great excess.
Citing ChatGPT without providing sources is not very valuable. I’m not sure the point as backed by science other than fertility and puberty: these are really important ones with many papers on it.
The problem with the phrase possible complications is that it comes up with masses of things. I have been on over a gram of melatonin a night for over a year and as far as I am concerned I intend to continue with this.
I have been doing a weekly blood panel now for almost 3 years whilst varying at lot of what I do and have identified only positives from Melatonin.
Melatonin’s role in delaying puberty is part of what it does. It holds back damage to mitochondrial DNA which delays the development clock (in my hypothesis of what the development clock is).
For example where girls have Hypothalamic hamartomata you get a reduction in melatonin and precocious puberty.
That is not a bad side effect of melatonin it is one of its functions in the body. As far as I am concerned aged as I am 65 I don’t expect to go through puberty in reverse as a result of taking melatonin.
In fact because puberty is an interplay between mRNA splicing changes and hormonal changes I think it would be hard to reduce fully even by turning the development clock right back.
Melatonin’s effects on fertility are more complex and it is probably best timed to suit ovulation and protection of both the ovaries and the eggs.
You are right. I erased links to the papers to make it shorter silly me. Melatonin dosing is not well researched unfortunately.
Just seing this study now, the RRs are crazy good: “melatonin use was associated with a reduced risk of developing AMD (RR, 0.42; 95% CI, 0.28-0.62) […] melatonin was associated with a reduced risk of AMD progression to exudative AMD (RR, 0.44; 95% CI, 0.34-0.56)”.
This paper is cited in: Melatonin protects retinal pigment epithelium cells against ferroptosis in AMD via the PI3K/AKT/MDM2/P53 pathway 2025
And in Melatonin stabilizes atherosclerotic plaques: an association that should be clinically exploited 2024. @AnUser, is it clinically relevant?
On AMD and PD:
- Incidence and risk factors of age-related macular degeneration in patients with Parkinson’s disease: a population-based study 2024: “Our findings suggest that the AMD incidence is higher in patients with PD than in the general population, with varying patterns of sex differences across age groups.”
- The association between age-related macular degeneration and risk of Parkinson disease: A systematic review and meta-analysis 2024: “The pooled analysis revealed a significant increase in the risk of developing PD for individuals with age-related macular degeneration (hazard ratio [HR] = 1.44; 95% confidence interval [CI]: 1.22–1.71; I2 = 47.3%).”
- Increased risk of Parkinson’s disease amongst patients with age-related macular degeneration and visual disability: A nationwide cohort study 2023: “Additionally, an increased risk of PD was observed in individuals with AMD compared with controls, regardless of the presence of VD (aHR 1.23, 95% CI 1.16–1.31).”
- Increased risk of Parkinson’s disease among patients with age-related macular degeneration 2021: “After adjusting for potential confounders, there was a higher risk of developing PD in the AMD cohort than in the non-AMD cohort (adjusted HR = 1.35, 95% CI = 1.16–1.58).”
- Association of Age-Related Macular Degeneration on Alzheimer or Parkinson Disease: A Retrospective Cohort Study 2020: “Compared to non-AMD participants, AMD patients had higher risk for AD (aHR 1.48, 95% CI 1.25-1.74) and PD (aHR 1.46, 95% CI 1.14-1.88).”
- Increased Risk of Parkinson Disease Following a Diagnosis of Neovascular Age-Related Macular Degeneration: A Retrospective Cohort Study 2014: “the hazard ratio of Parkinson disease during the 3-year follow-up period for subjects with neovascular AMD was 2.57 (95% CI: 1.42-4.64) that of comparison subjects.”
Looks like mechanistic speculation, so not at all.
I wasn’t sure which thread to put this under so l figured this is as good as any.
I have been using high doses of melatonin (100 to 500 mg and more) since September 2024. I have had weird nerve pain problems for at least the last 5 years (mainly sciatic but others too). Anytime l would bend down to pick something up l ran the risk agitating the nerve and it could last 2 to 6 weeks. During the day easily dealt with but at night it would make it almost impossible for me to sleep.
Around December l started noticing my nerves seemed to be becoming more resilient. I pushed it a bit too hard in February 2025 and had a 3 week stint of pain but other than that it seemed to be getting progressively better even now.
I have done exercises in the past and if l pushed a little too much it could cause a flare up.
To be completely upfront, as stated previously l am performing many interventions including rapa and it could be all interventions synergistically or none at all but l attribute these positive effects to the melatonin.
I still have a fair amount of issues that l am trying
to address but to paraphrase Dr. Reiter “melatonin is pretty good”.
@John_Hemming how do you take 1g of melatonin. I find the powder very bitter and hard to keep up on a daily basis. Even with yogurt it makes the yoghurt bitter.
I take a lot of pills. 20 60mg pills now 10 12mg and 15 20mg. It was 10x12 10x20 + 10x10 = 1200+120+300=1620mg
Where from? I’m also in Aus
I thought you took the powder form…
Rarely. I tried mixed with malt whisky. It put me to sleep.
Weird Italian-Argentinian paper:
Patients and Methods: This study evaluates the safety and efficacy of a neuroimmune regimen comprising melatonin (100 mg/day at night), 5-methoxytryptamine (30 mg in the early afternoon), angiotensin 1– 7 (0.5 mg twice daily), and cannabidiol (20 mg twice daily) in 306 patients with NCDs, including advanced cancer, autoimmune diseases, neurodegenerative disorders, depression, and cardiovascular disease.
Results: The neuroimmune regimen successfully halted cancer progression in 68% of cancer patients, who also reported improvements in mood, sleep, and relief from anxiety, pain, and fatigue. In patients with autoimmune diseases, the treatment effectively controlled the disease process, remarkable in cases of multiple sclerosis. Additionally, positive outcomes were observed in patients with Parkinson’s disease, Alzheimer’s disease, and depression.
On fertility:
Chinese paper, male mice: Melatonin ameliorates RF-EMR-induced reproductive damage by inhibiting ferroptosis through Nrf2 pathway activation 2025
Iranian preprint, female humans: Melatonin treatment results in progression of endometrial thickness in infertile women in IUI cycle 2025: “In general, administration of melatonin for 4 weeks in infertile women undergoing IUI cycle had beneficial effects on endometrial thickness, which was associated with better pregnancy outcome.”
my “lifetime” supply of melatonin arrived lol. 33333 doses according to this, 92 years at the recommended dose.
Effects of melatonin implants on the rate of pseudopregnancy in high yielding dairy goats 2025
ChatGPT explanation:
- Pseudopregnancy (PPG) is the accumulation of sterile uterine fluid together with a persistent corpus luteum; it prolongs anoestrus and causes temporary infertility. On commercial dairy farms the condition typically affects 6–30 % of does and may cluster in specific years or management systems
- A year-long field study on five Portuguese dairy-goat farms (2023-24) shows that giving does one 18-mg slow-release melatonin implant four to six weeks before buck introduction slashed pseudopregnancy (hydrometra) rates from the usual 7–10 % down to <1 %. Compared with natural, untreated cycles the odds of pseudopregnancy fell ~15-fold, and compared with a standard progesterone-CIDR induction protocol they fell ~40-fold. Primiparous does were still the most vulnerable group, but even they benefitted markedly from melatonin. The work suggests that, in high-yielding herds where intensive progesterone programmes are common, swapping those protocols for pre-breeding melatonin could improve fertility, shorten kidding intervals and reduce veterinary interventions.
It taste terrible lol. I feel like I’ve to force myself.
I had such a tiny amount I couldn’t taste anything. I dipped a spoon in and then shook off as much as I can. Just a bit of dust stuck to it. Already feel it. I’m unsure how to properly dose this.