It is very hard to predict dose from C Elegans studies - if someone would like to, then one can look that dose of Allantoin is 2.5 times higher than Rapamycin and choose the dose from this - ideally it should be tested in mice combined with Rapamycin and Rifampicin
From this paper it seems like:
Both Rapamycin and Allantoin gives 20% lifespan extension in worms
Rapamycin + Allantoin gives 5% lifespan extension (so this synergy requires also Rifampicin, otherwise it cancels Rapamycin effect - probably Rapamycin and Allantoin work on similar pathways - maybe with lower dose it would synergize better)
Some synergies are conserved in Drosophila
The idea is that this combination increase MUFA:PUFA levels in cells and cell membranes are less prone to damage so it slows damage
Ideally there should be a blood test for lipid peroxidation of erythrocyte membranes and one should choose the dose based on that
Please don’t go from worm studies to human experiments. The commonly used invertebrate models of aging are, IMO, not too good even for basic research, and will miss distribution and toxicity issues when applied to humans.
For example, long term rifampicin sometimes causes liver damage.
From memory, allantoin is probably pretty safe in low doses and may overlap a lot with metformin. Also from memory, there is rodent research on antidiabetic effects and a single human kinetic study. Take both with a grain of salt.
This is an interesting compound but has it ever been through clinical trials?
The percentage of compounds that work well in humans after testing in nematodes is very low. I spoke with Matt kaeberlein at a conference on aging last December and he commented that anyone taking drugs based on c-elegans data is taking very high risks. He really thought it was a bad idea. I tend to agree.
Allantoin increases in different stress conditions and environment such as physical activity, amniotic fluids and oxidative stress. So, we inspired to explore the role of allantoin as a metabolic by-product in health improvement and protection using irradiation as simulator for oxidative stress. Allantoin was injected i.p. (100 mg/kg) in senile male rats in irradiated and non-irradiated groups in comparison to sham operated group. The studied parameters were superoxide dismutase, Glutathione reductase, Glutathione, total antioxidant capacity, collagenase, urea, creatine kinase, alanine transaminase, aspartate aminotransferase, triglycerides, total cholesterol, and HDL and LDL cholesterol. Allantoin in vitro antitumor activity was MTT assayed for some age dependent cancers. Allantoin showed improvement in all in vivo studied oxidative stress parameters. Allantoin showed an increase in lipogenesis was recorded as a hepatic energy targeting muscles. Allantoin improves aging process indicated by its collagenase inhibitory effect. Allantoin showed cytotoxicity against prostate, colon, intestinal ovarian and breast cancers and weak inhibitory against larynx cancer. Allantoin may be the possible mysterious key factor involved in health and aging improvement and cancer protection in stress conditions such as physically activity and radiation hazards.
Allantoin is extracted from the comfrey root and is often synthetically derived. It is added to many products to treat burns, dermatitis, wounds, acne, and impetigo. Allantoin is also added to sensitive skin moisturizers and hand sanitizers, and in topical formulations for the treatment of scars and keloids. It is carcinogenic and thus contraindicated in pregnancy and lactation, and can be fatal when orally consumed.
The growing consumer demand for all-natural ingredients in foods and over-the-counter products has increased interest in botanicals for skin care (Table 2-8). There is little evidence from human trials to support their efficacy, and the rigorous processing prior to their inclusion in cosmeceuticals often depletes the beneficial properties of the extract. Despite this, the use of botanicals is widespread and will continue to expand as the demand for natural products increases.
My grandmother, who lived to 98 drank comfrey tea and was a strong believer in it. My understanding is the root, when heavily consumed can cause issues. It seems not consuming more than was in a cup of tea would be less risky than more consumption without more study.