Most diabetes tablets push insulin out regardless of whether you need it, which is where low blood sugar comes from.
Sitagliptin extends the life of hormones your gut already releases after eating — and those only act when sugar is raised.
Without prescription, plain packaging. One tablet daily, well tolerated.
Something odd happens when you eat. Glucose swallowed produces a much larger insulin response than the same glucose given into a vein.
The gut is doing something extra. When food arrives, cells in the intestinal lining release hormones called incretins.
Those hormones do several useful things: they prompt the pancreas to release insulin, they suppress glucagon which would otherwise tell the liver to pump out more glucose, they slow stomach emptying, and they reduce appetite.
Here is the catch. An enzyme called DPP-4 destroys them within a couple of minutes.
Blocking the enzyme instead
Sitagliptin blocks DPP-4. The incretin hormones survive longer and keep working.
So the drug does not add anything to the system. It stops your own hormones being cleared so fast.
And this is the clever part: the incretin effect is glucose-dependent. It only stimulates insulin when blood sugar is actually raised. When sugar is normal, nothing happens.
Which means that on its own, this almost never causes low blood sugar. That is a meaningful advantage over older tablets that push insulin out regardless.
Where it fits
Type 2 diabetes where metformin is not enough
People who cannot tolerate metformin
Anyone for whom hypoglycaemia is a particular concern — older people, those living alone, drivers
In combination with other tablets or with insulin
It is weight-neutral, which also distinguishes it from some alternatives that cause weight gain.
Taking it
One tablet daily.
Any time of day, with or without food.
Same time each day.
Missed dose: take it when you remember unless the next is close.
Reduced kidney function means a lower dose, so kidney tests are checked before starting and periodically after.
The number that tells you whether it is working
A single glucose reading is a snapshot of one minute. HbA1c is a summary of the last few months.
It measures how much of your red blood cell pigment has become permanently bound to glucose. Red cells live a few months, so the result averages across that period.
Which means you cannot fix it with a disciplined week before the test. Day-to-day habits are what show up.
And after a change in treatment, it takes a few months before the number reflects the new situation.
Two things to report
Pancreatitis. Uncommon but important. Severe, persistent abdominal pain boring through to the back, usually with vomiting, that does not ease. That needs urgent assessment.
Severe joint pain. Reported with this class, sometimes months after starting. It resolves after stopping, but it is almost never connected to the tablet because of the delay.
Possible side effects
Headache
Upper respiratory symptoms, sore throat, blocked nose
Nausea
Abdominal discomfort
Occasional rash
Generally one of the better tolerated diabetes tablets. Low blood sugar becomes a real possibility when it is combined with insulin or sulfonylureas, and in that case the other drug's dose may need reducing.
Check your feet. Every day.
It sounds excessive until you know why.
Raised blood sugar damages small nerves over time, and sensation in the feet fades so gradually that people do not notice it going. A blister, a stone in the shoe or a small cut then goes unfelt.
Circulation is often poorer too, so the wound heals slowly. A trivial injury turns into a serious problem.
Look at your feet daily, including between the toes and underneath
Use a mirror, or ask someone
Shoes that fit, never tight
Shake out your shoes before putting them on
Do not walk barefoot
Any wound that is not healing quickly gets seen
What moves the needle most
Movement — muscle takes up glucose without needing insulin
Weight loss, particulary around the middle
Fewer refined carbohydrates
Fibre, which slows absorption
Regular meal timing
Sleep, which has a bigger effect on glucose control than people expect
A walk after eating blunts the post-meal spike noticeably. It is the simplest and most underrated thing on the list.
Ordering without prescription: how it works
Long-term daily treatment works best when the supply never lapses.
Pick the strength and the pack size, put in a delivery address, confirm. Couple of minutes, any time of day, no queue and no conversation across a counter.
It goes out in plain packaging. No pharmacy name on the outside, nothing that hints at what is inside. How long delivery takes depends on where the parcel is headed.
On price it comes down to strength and pack size. Larger packs generaly work out better per unit.
Nothing is asked of a UK buyer beyond an address. No prescription to upload, no consultation, nobody ringing back to ask questions you did not invite. You pick the strength, you pick the quantity, that is it.
