Grape Seed Extract is surprisingly uneventful. The molecules in GSE are known as procyanidins, and these are chains of catechins. Think of a 'catechin' as a basic molecule structure, forming what we know as green tea catechins. The basic catechin molecule known as (+)-catechin makes up these procyanidin chains in GSE.
The majority of GSE is actually just metabolized from linear chains of catechins into free catechins, so the benefits associated with GSE are highly similar to benefits with other high anti-oxidant foods. There is some unique benefits of the chains per se before they get metabolized, and these chains are absorbed to a very small degree. Superloading GSE at 2g a day might confer unique benefits, but the majority of benefit associated with GSE does not appear to be unique to the molecule or overly potent.
Royal Jelly is an interesting one, a concoction made in a manner similar to bee vomit and used for purposes similar to bee breast milk. It contains testosterone (not 'increases', actually 'contains'), but at a concentration where it probably doesn't mean much and is just marketing. It has been shown to increase testosterone and benefit circulating lipids, but the benefits seen with Royal Jelly are quite unreliable. It doesn't help that we have not located the 'main' molecule causative of many known effects.
Although Royal Jelly appears to be a very slight boost in the right direction with small doses and potentially a pro-longevity agent (life to years, rather than years to life) its unreliability makes it hard to draw conclusions.
Spirulina is the last update, and this one is surprisingly potent.
Spirulina is 55-70% protein by weight (vegan source of protein) and 20% of the total weight is a protein subclass of 'C-Phycocyanin'. In this subclass is the active molecule called Phycocyanobilin which is 1% of Spirulina by total weight (3g Spirulina contains 30mg Phycocyanobilin)
Spirulina is the only molecule I have seen that exerts benefits via the very general and uneventful 'anti-oxidant' mechanism of action, but relatively low doses of Spirulina in animals have, in some instances, outright abolished toxin-induced neurological disorders. The novel mechanism of action of phycocyanobilin, known as NADPH oxidase inhibition, appears to be very potent in the body.
It is also a selective COX2 inhibitor (secondary to NADPH oxidase inhibition), with an in vitro efficacy similar to the pharmaceutical celecoxib; reduces blood glucose in one rat study slightly less potently than metformin; reduced pain in one study and slightly underperformed ibuprofen at the same dose; slightly underperformend Triamcinolone at suppressing arthritis in rats; and week-long treatment was about the same as the ACE inhibitor captopril. The fact that Spirulina is in the same class as some of these reference drugs is surprising, the fact that Spirulina is in the same class as all of these reference drugs is remarkable.
It does have a few human studies on it, and it appears to be showing efficacy at improving parameters of glucose metabolism (HbA1c and insulin sensitivity) and lipid metabolism (triglycerides, lipoproteins) and improving the state of a fatty liver (case studies). The promising neurological benefits have not yet been replicated in humans.
Overall, its actions appear to be incredibly promising. It seems to be a very good 'metabolic bandaid' supplement (to be taken if in an unhealthy state) and a few studies in rats suggest that benefits may be attenuated if the healthy lifestyle is not stopped, but they are not abolished.