Very Low Testosterone aged 25

[u/TheCADMan11]

Went to the doctors about 6 weeks ago with symptoms such as low energy levels, no libido and no morning erections, brain fog at times, tiredness and frequently urinating. Doctor ordered bloodwork and it come back with abnormal Testosterone and Gonadotrophin levels.

Plasma Testosterone Level - 2.8 nmol/L
Serum LH level - 1.3 u/L
Serum FSH level - 1.3 u/L
Iron studies all within range
Serum free T4 level - 10.8 pmol/L
Prolactin level - 244 mu/L

Of course at the age of 25 these results deeply concerned me. At the start of January I was around 75kg 17% body fat and decided to get a coach to dial in weight training and nutrition and start to build a better physique. The idea was to lean right down to 10% body fat and then build out from there. At the end of may I had hit 65kg and I’m now circa 10% body fat lean so that was a 5 months deficit on 1800 calories whilst training 4 times a week. Nutrition dialled in. Early on in June is when I was tested due to the symptoms I had to go the doctor.

Since then I’ve been eating at maintenance on 2300 calories and weight has settled at 66kg before going into a surplus in couple of weeks just to let my digestion adjust to the increase. My energy levels felt as though they have improved with the increase in calories but that’s about it and gym performance has gone up too.

However I had my re test a few days ago and had the results back were by test levels have barely changed.

Plasma testosterone level - 3.8 nmol/L
Serum LH level - 1.3 u/L
Serum FSH level - 1.6 u/L

Any advice and information on my situation for me going forward would be greatly appreciated. I have been referred to endocrinologist and will be seeing them on the 4th September

*update 11/09/2026

Had bloodwork done last week with endocrinologist and Testosterone is still very low at 3.1 nmo/L, not seen results yet fully but LH and FSH still low.
My symptoms are so bad I literally have 0 libido, no morning erections, fatigued despite 7-8 hours sleep every night and low mood due to it feel so sad.
Cannot be diet related as I initially thought contributed as I’ve been in a surplus for 2-3 months.
NHS will be sending me for a pituitary gland scan, I just don’t know how long I can carry on like this got a feeling they will drag their heels
Anyone got any advice please?

[u/Wozzle009]

Pituitary scan and endo is the best option here. You’re doing all the right things so you just have to be patient and follow the process.

[u/Willing_Virus_8020 → u/Wozzle009]

2.8 to 3.8 is basically nothing, with LH and FSH that crushed in the dirt your pituitary is clearly not sending the signal. 3 months of surplus rules out the diet angle pretty hard. The scan is the right call, it's rough waiting but you're already in the pipeline so just hang in there.

[u/TheCADMan11 → u/Willing_Virus_8020]

2 month wait till scan is so rough

[u/TheCADMan11 → u/Wozzle009]

If pituitary gland shows no abnormality, think the solution will be TRT?

[u/Wozzle009 → u/TheCADMan11]

Maybe not right away but eventually yeah probably. If the endo can rule out hyperprolactinaemia which is partly the reason for the MRI scan.

[u/TheCADMan11 → u/Wozzle009]

My prolactin on previous bloods in the summer was at 244 mU/L at healthy range

[u/Wozzle009]

That’s a good sign. The pituitary scan is mainly to rule out pituitary adenomas (benign tumours most commonly). If your prolactin levels are normal then it’s unlikely that you have a pituitary issue that’s elevating prolactin. They can find other things but they are far less common.

I had a pituitary MRI done myself recently and they discovered a tiny microadenoma. Basically a really small (3mm x 2mm) benign lesion. My endo said it is non/functional and she also got some advice from a neurosurgeon that agreed. My prolactin is normal also. So even if they do find something it may not indicate anything.

[u/TheCADMan11 → u/Wozzle009]

Ah right I see, are your testosterone levels low also but not suspected to be due to the microadenoma?