Molasses is the thick dark syrup left over when sugar cane is refined into sugar. Blackstrap molasses — the last and darkest grade — is taken as a supplement for its iron, calcium, magnesium and potassium. It is a food, not a medicine, and it is still mostly sugar.
What is Molasses?
Molasses is a food product, not a registered medicine, so it does not appear in the South African Medicine Price Registry. That is expected and says nothing about its quality.
It is made during sugar refining. Cane juice is boiled to crystallise out sugar; what remains after each boiling is molasses. Three grades result, and the difference matters:
- Light (first) molasses — after one boiling. Sweetest, mildest, lowest in minerals.
- Dark (second) molasses — after two. Less sweet, more robust.
- Blackstrap molasses — after the third and final boiling. The darkest and least sweet, with a distinctly bitter edge, and by far the highest mineral content.
Blackstrap is the one sold as a supplement, and if a bottle does not say blackstrap, it is probably one of the lighter grades and contains meaningfully less of what people take it for.
Its appeal is that it concentrates what the cane took from the soil. The minerals that do not crystallise with the sugar end up in the syrup. Blackstrap is a genuine dietary source of iron, calcium, magnesium, potassium and manganese, along with some B vitamins.
The unavoidable qualification: molasses is still roughly half sugar by weight. A tablespoon carries most of the sugar of a tablespoon of syrup, because that is essentially what it is. Any mineral you get, you get alongside that.
What is Molasses commonly used for?
Traditional and popular uses include:
- Iron intake, particularly in people avoiding red meat or managing mild iron deficiency.
- A general tonic, often taken by the spoonful daily.
- Constipation, where its magnesium content and sugar draw water into the bowel.
- Menstrual symptoms, a long-standing folk use with little formal evidence.
- Bone health, for calcium and magnesium.
- A less-refined sweetener in baking and cooking.
- Muscle cramps, attributed to its potassium and magnesium.
What the evidence supports is narrower than the claims made for it. Blackstrap molasses is a real source of several minerals — that part is simply true, and it is measurable on a nutrition panel. What it is not is a treatment.
The iron question deserves a straight answer, because it is why most people take it. Molasses contains non-haem iron, the plant form, which the body absorbs far less efficiently than the iron in meat. It can contribute to iron intake. It will not correct diagnosed iron-deficiency anaemia, which needs proper iron supplementation at therapeutic doses and — more importantly — an explanation for why the iron is low. Anaemia is a finding, not a diagnosis, and in adults it can be the first sign of bleeding that needs investigating. Treating it with syrup can delay that.
Who commonly looks for Molasses and why
- People wanting a “natural” iron source, uneasy about iron tablets or their constipating effect.
- Vegetarians and vegans, looking for plant sources of iron and calcium.
- Women with heavy periods, who are at genuine risk of iron deficiency — and who should be assessed rather than self-treating.
- People with constipation, using it as a gentle home remedy.
- Parents, who were given it as children by their own parents. It has a long history as a household tonic in South Africa.
- People avoiding refined sugar, treating it as the less-processed option — which is true in a narrow sense and beside the point in a broader one.
- Athletes and gym-goers, for potassium and magnesium around cramping.
The honest framing for most of these: molasses is a reasonable food to include, and a poor substitute for a diagnosis.
What to check on the label before taking Molasses
- Does it say blackstrap? If not, expect considerably lower mineral content.
- Is it unsulphured? Sulphur dioxide is used as a processing aid and preservative in some molasses. Unsulphured products have a cleaner taste, and sulphites can trigger reactions in sensitive people, particularly some people with asthma.
- The nutrition panel — iron, calcium, magnesium and potassium per serving, and what a serving actually is. This is the only way to know what you are getting.
- Total sugar per serving. It will be high. Decide with that number in front of you.
- Any added ingredients — some products are blended with cane syrup or glucose.
- Whether it is food-grade and intended for human consumption. Molasses is also sold as animal feed and as a garden and industrial product, and those are not the same thing.
- The manufacturer and expiry date, and storage instructions after opening.
Safety, interactions and when to seek professional advice
For most people, molasses in ordinary food amounts is safe.
Take particular care if you:
- Have diabetes or prediabetes. This is the main caution. Molasses is a sugar syrup and raises blood glucose. Its being unrefined does not change that. Speak to your doctor or a dietitian before taking it daily.
- Have kidney disease. Blackstrap is high in potassium, and people with reduced kidney function may need to limit potassium intake — sometimes strictly.
- Take potassium-sparing diuretics, ACE inhibitors or ARBs for blood pressure, which raise potassium levels themselves.
- Have irritable bowel syndrome or a sensitive gut — it can cause bloating, cramping and loose stools.
- Have asthma or sulphite sensitivity — choose unsulphured.
- Take iron, calcium or magnesium supplements already, or thyroid medicine, tetracycline or quinolone antibiotics, whose absorption calcium can reduce. Separate them by a couple of hours.
- Are giving it to a child. Do not give molasses, or any syrup or honey, to an infant under twelve months.
- Have dental concerns. It is sticky, sugary and clings to teeth. Rinse afterwards.
Side effects are usually limited to loose stools, bloating or cramping when too much is taken at once.
See a doctor rather than self-treating if you have symptoms of anaemia — persistent tiredness, breathlessness on mild exertion, pallor, dizziness, brittle nails or unusual cravings for ice or non-food items. A blood test settles it, and the important question is not only whether iron is low but why. See a doctor too for constipation lasting more than a couple of weeks, any change in bowel habit, blood in the stool, or unexplained weight loss.
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Frequently asked questions
What is molasses used for? As a dietary source of iron, calcium, magnesium and potassium, as a general tonic, as a home remedy for constipation, and as a sweetener. Blackstrap is the grade highest in minerals.
Is blackstrap molasses different from ordinary molasses? Yes. Blackstrap comes from the third boiling and has the highest mineral content and the least sugar. Lighter grades are sweeter and much lower in minerals.
Will it fix my anaemia? No. It can contribute to iron intake, but it will not treat diagnosed iron-deficiency anaemia — and anaemia needs a cause established, not just topping up.
Is it healthier than sugar? It contains minerals that refined sugar does not. It is still around half sugar and affects blood glucose accordingly.
Can I take it with diabetes? Speak to your doctor or dietitian first. It is a sugar syrup, however unrefined.
Does it help constipation? Some people find it does, through its magnesium and sugar content. Persistent constipation should be assessed rather than managed indefinitely at home.
Can I give it to my baby? Not under twelve months. Avoid molasses, syrups and honey in infants.
How much should I take? There is no established supplement dose — it is a food. Most people take a spoonful or two daily, and the sugar content is the practical limit.