The Reservoir Formula Ingredients: What Is Inside and Why

Most people arriving at an ingredients page have already seen an advertisement and want to check it before deciding. That is exactly the right instinct, and this page is written for it: what is in The Reservoir Formula, what each thing is doing, and why several popular ingredients are absent.

Everything below is on the Supplement Facts panel, and the panel is on the product page. Nothing here needs to be taken on trust, and the point of the article is to make the checking easier rather than to replace it.

Ten ingredients, and why not thirty

The formula holds ten actives. That is a deliberate number rather than an accident of budget, and the reasoning behind it is worth stating first because it explains every choice that follows.

A capsule has a fixed volume. Every ingredient added to it takes space from the others, which means a long list is always a list of small amounts. Thirty ingredients in a two capsule serving is thirty tokens rather than thirty doses, and the effect of that is to produce a label that reads impressively and delivers a fraction of everything on it.

The alternative is to decide what job the product is doing and include only what the job requires. Here the job is a reserve rather than a blood count, and rebuilding a reserve has three steps: absorb the iron, convert it into a usable state, and store it. Each of the ten is there for one of those three steps. Nothing is present because the audience associates it with hair.

The second consequence of that decision is that there is no proprietary blend anywhere on the panel. A blend discloses only the combined weight of everything inside it, which means any individual amount can be arbitrarily small without the label ever saying so. Every figure below is printed individually, which is the only way a comparison against anything else is possible at all.

There is a third consequence worth naming, since it is the one that shows up months later rather than on the shelf. A short list is easier to hold constant. A long one invites substitution, because when a single component becomes expensive or scarce the pressure is to swap it quietly for a cheaper equivalent and leave the label looking similar. Ten named ingredients with individual figures make that kind of drift visible to anyone comparing two bottles bought a year apart.

Iron, and why bisglycinate rather than a salt

Iron cannot be put into a capsule on its own. It is always bound to a partner molecule, and that partner determines both how much of the dose crosses the gut wall and how the remainder behaves on the way through.

The Reservoir Formula uses iron as ferrous bisglycinate, at 45 mg of elemental iron per serving. Two parts of that sentence deserve unpacking.

Bisglycinate means the iron is bound to two molecules of the amino acid glycine, forming a chelate. The bond holds further along the digestive tract rather than dissociating early in stomach acid the way a mineral salt does. Less free iron loose in the gut is the mechanism behind the difference in tolerance, and tolerance is not a comfort question on a course that has to run for months: it decides whether the course is finished at all. The chemistry is set out in Chelated Iron and Iron Salts.

Elemental means the figure is the weight of the iron itself, not the weight of the whole compound. This distinction is where most label comparisons go wrong. A bottle can print 325 mg on the front and deliver 65 mg of iron, because the larger number is the compound and the smaller one is the metal inside it. When comparing this formula against anything else, the elemental line is the only line that compares.

The dose itself sits at 45 mg of elemental iron per two capsule serving. That figure is chosen for a reserve being rebuilt over months rather than for an anemia being corrected quickly under supervision, which are two different briefs with two different dose logics. Absorption is capped per dose regardless, and the fraction that does not cross the gut wall continues down the tract and produces most of the symptoms that end courses early. A moderate dose taken for four months moves a reserve considerably further than a large one abandoned in week three.

Lactoferrin, and what it is doing here

Lactoferrin is a protein whose function is to bind iron and move it, and it appears in this formula at 100 mg per serving.

Its relevance to a reserve specifically, rather than to iron generally, is where it acts. Absorbing iron and storing iron are two different problems, and a supplement that solves only the first leaves the second to chance. Lactoferrin operates at the point where iron is handled and directed rather than left circulating, which is the step that separates a dose taken from a level raised. The detail is in What Lactoferrin Actually Does With Iron.

The practical reason it appears on so few labels is cost. Lactoferrin is by a considerable distance the most expensive ingredient in this formula, which is why it is far more common to see it named on the front of a bottle than given a milligram figure on the back. A product that mentions lactoferrin in its marketing without a number on the panel is saying it is present and declining to say how much, and unknown is not the same as adequate.

The check takes five seconds on any product including this one: find lactoferrin on the Supplement Facts panel, and see whether there is a figure next to it.

One point of honesty about lactoferrin that belongs on a page like this. It is a protein derived from milk, which means anyone avoiding dairy proteins entirely should know it is in here. It is not lactose and the two are frequently confused, but the distinction matters to the people it matters to, and it is better read on a page than discovered on a label.

L-Lysine, the cofactor most formulas leave out

L-Lysine appears at 400 mg per serving, as L-Lysine HCl, and it is the ingredient people ask about most because it is the one they did not expect.

It is included because iron supplementation does not always work, and one of the reasons it does not always work sits with lysine. There is published work examining lysine alongside iron in women whose ferritin failed to respond to iron alone, and the reasoning is that a shortfall in the amino acid can limit what the iron is able to do once it arrives. What that means in practice, and where the evidence stops, is in What L-Lysine Is Doing in an Iron Formula.

It is also the ingredient that most clearly illustrates the volume argument from the top of this page. At 400 mg it occupies real space in the capsule. A formula carrying thirty ingredients does not have 400 mg to give to any of them, which is why lysine at a meaningful amount and a thirty ingredient label are close to mutually exclusive.

A note on what lysine is not, since the ingredient carries a lot of unrelated claims elsewhere. It is not included here for anything to do with cold sores, immunity or athletic performance, all of which are separate literatures. It is present for the specific and narrow reason described above, which is what it is doing in an iron formula rather than in general.

The cofactors, and why the form of each one matters

Iron does not act alone. Five of the ten actives are there because the chain around iron has to function for the iron itself to be useful, and in each case the form is as deliberate as the amount.

Vitamin C, at 120 mg as calcium ascorbate, keeps iron in the chemical state the gut absorbs most readily. Its presence alongside iron is common enough that its absence from a label is worth noticing.

Copper, at 1 mg as copper bisglycinate, is required for iron to be mobilised out of storage and loaded onto its transport protein. That makes it specifically relevant to a reserve rather than to iron in general, and it is frequently missing from formulas aimed at anemia rather than at depletion.

Vitamin B12, at 100 mcg, is present as methylcobalamin rather than cyanocobalamin. Folate, at 400 mcg DFE, is present as L-5-methyltetrahydrofolate rather than folic acid. Vitamin B6, as pyridoxal-5-phosphate rather than plain pyridoxine. In all three cases the version chosen is the one the body already uses, rather than the one it has to convert first. A proportion of the population converts the cheaper forms inefficiently, and choosing the active form removes that variable rather than assuming it away.

B12 and folate sit at the point where iron becomes red blood cells, which is why a shortfall in either produces a picture that resembles iron deficiency and does not respond to iron. B6 is involved in the first committed step of building the molecule that carries iron through the blood.

Zinc and selenium, and the reason they are dosed low

Zinc appears at 10 mg as zinc bisglycinate, selenium at 55 mcg as L-selenomethionine. Both are modest figures and both are modest on purpose.

Zinc and iron compete for absorption. A high dose of zinc in the same capsule as iron works against the primary purpose of the product, which is why the amount here sits at a level intended to cover a requirement rather than to look impressive on a panel. This is a case where a larger number would be worse rather than better, and where a product boasting a high zinc figure alongside iron is advertising a conflict it has not resolved.

Selenium is present at a level near its daily value. It is one of the nutrients where the gap between an adequate intake and an excessive one is narrower than most people assume, and a formula intended to be taken daily for several months has a particular obligation not to be careless with it.

Taken together those five explain a structural point about the product. The reason it is a two capsule serving rather than one is arithmetic: 45 mg of elemental iron, 100 mg of lactoferrin and 400 mg of lysine alone account for the greater part of a capsule before any cofactor is added. A single capsule version of this formula would necessarily be a smaller version of it, and the choice was to keep the amounts and use the space rather than to keep the convenience and cut them.

One practical note on the zinc figure specifically, since it is the one people query. Because zinc and iron compete, the sensible reading of a low zinc number on an iron formula is that the formulator noticed the conflict. A high number on the same panel means either that they did not, or that they preferred the label to the outcome. Neither is a comfortable thing to conclude about a product taken daily for months.

Selenium is worth one more sentence for the same reason: it is dosed near its daily value rather than above it, because a formula built for months of continuous use has an obligation to be conservative with the nutrients where the useful range is narrow.

What is not in it, and why

The absences are as considered as the inclusions, and three of them come up constantly.

There is no biotin. Biotin is the default ingredient in products aimed at hair, and genuine biotin deficiency is rare. Where it is not present, supplementing it does not address a supply problem in the follicle. It also carries a practical drawback worth knowing: high dose biotin can interfere with certain laboratory immunoassays, including some thyroid tests, which is unhelpful in a situation where thyroid is one of the things worth ruling out. Including it would have made the label more familiar and the product no better.

There is no collagen. Hair is largely keratin, the mechanism connecting oral collagen to it is considerably less direct than the marketing suggests, and collagen occupies a great deal of capsule volume for what it delivers.

There is no botanical blend. Botanical blends are the standard way of lengthening an ingredient list without lengthening the useful part of it, and they are almost always sold as proprietary, which is what allows the individual amounts inside them to remain undisclosed.

Other ingredients on this product are vegetable cellulose, which is the capsule shell itself. It is a two piece capsule rather than a tablet, which means it opens where it is meant to rather than relying on a coating to break down.

Two more absences are worth a line each. There is no vitamin A, which appears in some iron formulas aimed at hair and which accumulates in the body in a way that makes daily long term use a question rather than a default. And there is no added calcium, for the plainest reason on this page: calcium competes with iron directly at the point of absorption, so putting the two in the same capsule would be working against the purpose of the product. Anyone taking a calcium supplement separately should keep an hour between it and this one.

What remains after all of that is a label that can be read in full in under a minute, which is the point. A panel nobody finishes reading is a panel that was not written to be read.

How to check all of this yourself

Everything above is a claim until it is verified against the panel, so here is the procedure, and it works on any product rather than only on this one.

Start at the serving size line, at the top of the panel, because every figure underneath it is per serving and a serving can be one capsule or four. Two products showing the same iron figure are not equivalent if one reaches it in one capsule and the other in three.

Then the iron line: the form in brackets, and the elemental figure with its percentage of daily value. Then lactoferrin: present or absent, and with a number or without one. Then the cofactor lines, reading the forms rather than only the amounts. Then a scan for the words proprietary blend anywhere on the panel.

Five checks, about thirty seconds, and the long version is in How to Read an Iron Supplement Label in Thirty Seconds. The criteria behind them are in Best Iron Supplement for Low Ferritin.

One last thing, and it matters more than any ingredient on this page. None of this is a reason to start taking iron. Iron accumulates rather than being freely excreted, and some people carry conditions that make loading actively harmful, which is why a ferritin test comes before a purchase rather than after one. What to ask for, and why a normal result can still describe an empty reserve, are in Low Ferritin Symptoms in Women.

References

1. MedlinePlus. Iron. National Library of Medicine.
2. MedlinePlus. Ferritin Blood Test. National Library of Medicine.
3. MedlinePlus. Vitamin B12. Medical Encyclopedia, National Library of Medicine.
4. MedlinePlus. Folic Acid. National Library of Medicine.
5. MedlinePlus. Zinc in Diet. Medical Encyclopedia, National Library of Medicine.

These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease. This article is for information only and is not medical advice. Talk to your healthcare professional.