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Short answer
To date, Himmense has received no reports of adverse side effects from customers taking BOOST. Every active in the formula sits inside published human-tolerability data, and the daily dose is designed to stay well within established safe-intake levels.
That said, no food supplement is risk-free for everyone. If you take prescription medication, have a diagnosed health condition (thyroid, diabetes, autoimmune, liver, kidney, or hormone-sensitive), are due surgery, or are under 18, speak to your GP or pharmacist before starting BOOST.
Last verified: 6 November 2026. This article is general information, not medical advice. Food supplements are not a substitute for a varied diet and healthy lifestyle. If you are taking medication or have a medical condition, consult your GP or pharmacist before starting any new supplement.
What Himmense customers report
BOOST has been in the hands of UK men since 2020. In that time, no customer has reported a side effect requiring us to act. Our Trustpilot page (4.8★ from 139 verified reviews on 6 November 2026) and Judge.me on-site reviews are open — the overwhelming tone is on energy, sleep and consistency, with no pattern of safety complaints.
We mention this not to claim BOOST can never cause anyone discomfort — your body and your medicine cabinet are unique to you — but because an honest public record matters more than a marketing claim.
Why BOOST is formulated the way it is
The formula is deliberately tight: 19 actives, each selected for a published human clinical trial and dosed in line with the amount the trial used. That also means every active was evaluated for tolerability in those same trials, at or above the dose we use.
- Patented, standardised extracts (KSM-66®, Testofen®, PrimaVie®, Tesnor®, ForsLean®, BioPerine®) — the specific branded forms carry their own published safety data, not just the generic herb.
- Vitamins and minerals sit inside UK Nutrient Reference Values (NRVs) where one is established.
- One capsule a day, taken with food — the format most likely to be well-tolerated.
Ingredient-by-ingredient tolerability
Here's every active in BOOST, the daily amount, and what the published tolerability data says.
| Active | Dose/day | Tolerability note |
|---|---|---|
| KSM-66® Ashwagandha | 300 mg | Trials to 600 mg/day over 8–12 weeks show high tolerability. Rarely: mild drowsiness, loose stools. Check first if you have a thyroid condition, autoimmune disease, or take sedative or thyroid medication. |
| Testofen® Fenugreek | 600 mg | Standardised Fenuside™ extract. Published safety data at this dose over 8–12 weeks. Can mildly affect blood-sugar control — check first if you take diabetes medication or anticoagulants. |
| PrimaVie® Shilajit | 300 mg | Purified, patented form. Tolerated in human trials at 200–500 mg/day for 90 days. Caution if you have iron-overload conditions (haemochromatosis). |
| Tesnor® (cocoa + pomegranate) | 200 mg | Three published human trials show good tolerability at 400 mg/day — we use 200 mg. |
| ForsLean® Coleus forskohlii | 250 mg (20% forskolin) | Mildly vasodilatory. Check first if you take blood-pressure or blood-thinning medication. |
| BioPerine® Black Pepper | 5 mg (≥95% piperine) | Absorption enhancer. Can increase the absorption of some prescription medicines — check with your pharmacist if you take anything daily. |
| Ginger | 500 mg (23:1 extract) | Food-grade. Mild antiplatelet effect — check first if on blood thinners. |
| Panax Ginseng | 100 mg (20:1, 50% ginsenosides) | Can affect blood sugar and may interact with blood thinners, MAOIs, or diabetes medication. |
| Tribulus Terrestris | 50 mg (9:1, 40% saponins) | Low dose. Trials to 1,500 mg/day show good tolerability. |
| Maca Root | 100 mg (100:1 extract) | Food-grade root. Human trials to 3 g/day show good tolerability. |
| Zinc (as citrate) | 15 mg (150% NRV) | Below the EFSA tolerable upper intake (25 mg/day). Long-term intake above 40 mg/day can reduce copper absorption — not relevant at this dose. |
| Magnesium (as bisglycinate) | 110 mg (29% NRV) | Bisglycinate is the form least likely to cause loose stools. Well-tolerated at this dose. |
| Selenium (as selenomethionine) | 8.25 μg (15% NRV) | Comfortably below the EFSA upper limit (300 μg/day). |
| Vitamin D3 (algae) | 25 μg / 1,000 IU (500% NRV) | Below the EFSA upper limit (100 μg/day). Public Health England recommends 10 μg/day for UK adults year-round. |
| Vitamin C | 12 mg (15% NRV) | Small supportive dose; well within safe intake. |
| Vitamin E | 1.8 mg (15% NRV) | Well within safe intake. |
| Vitamin B6 | 1.3 mg (93% NRV) | At the NRV. Concern for peripheral neuropathy only arises at >200 mg/day long-term — not at this dose. |
| Vitamin B12 (methylcobalamin) | 2.5 μg (100% NRV) | Water-soluble; excess excreted. |
| Folate (as L-5-MTHF) | 200 μg (100% NRV) | Active form; well within safe intake. |
Who should check with their GP or pharmacist before starting BOOST
A short honest list. If any of these apply to you, don't start BOOST without a brief conversation first:
- You take prescription medication daily, particularly blood thinners (warfarin, apixaban, rivaroxaban), diabetes medication, thyroid medication, blood-pressure medication, sedatives, antidepressants, or hormone-modifying drugs.
- You have been diagnosed with a thyroid condition, diabetes, an autoimmune condition, liver or kidney disease, haemochromatosis, or a hormone-sensitive condition such as prostate cancer.
- You are due surgery within the next two weeks — some herbal actives can mildly affect clotting and should be paused before anaesthetic.
- You are under 18. BOOST is formulated for adult men.
- You are trying to conceive with a partner who is or may be pregnant, or sharing supplements with a woman — BOOST is formulated specifically for men and is not suitable during pregnancy or breastfeeding.
Common interactions, at a glance
| If you take… | Reason to check first |
|---|---|
| Blood thinners (warfarin, apixaban, rivaroxaban, aspirin) | Fenugreek, ginger, ginseng, forskolin can mildly affect platelet function. |
| Diabetes medication (metformin, sulfonylureas, insulin) | Fenugreek and ashwagandha can mildly affect blood sugar. |
| Thyroid medication (levothyroxine) | Ashwagandha can affect thyroid hormone levels. |
| Blood-pressure medication | Forskolin is mildly vasodilatory. |
| Sedatives, SSRIs, or sleeping tablets | Ashwagandha has mild sedative properties. |
| Immunosuppressants | Ashwagandha can modulate immune activity. |
| Any daily medication (general) | BioPerine® (piperine) can increase absorption of some drugs — ask your pharmacist if your prescription is time- or dose-sensitive. |
If you take any of the above, a quick conversation with your GP or pharmacist is a 5-minute call that's worth having before starting anything new.
How to take BOOST to minimise any risk of discomfort
- One capsule a day, with your evening meal. Taking it with food is the single biggest thing you can do to avoid any mild digestive discomfort.
- Don't exceed one capsule per day. The dose was set deliberately. More is not more.
- Don't stack BOOST with another testosterone-support formula. You'll end up duplicating zinc, magnesium, vitamin D, ashwagandha and fenugreek — above intended intake with no additional benefit.
- Give it 90 days before judging effect. Patented botanical trials ran 8–12 weeks; your body deserves the full window to respond.
What to do if you notice anything
Pause the supplement, and if symptoms persist seek medical advice. Email us at hello@himmense.com with what you noticed so we can log it and advise.
Stop immediately and seek urgent medical advice for: facial swelling, breathing difficulty, rash spreading rapidly, persistent vomiting, jaundice, severe abdominal pain, or any marked change in mood. These are rare, but applicable to any food, supplement or new routine.
Frequently asked questions
Does Himmense BOOST have side effects?
To date, Himmense has received no reports of side effects from customers taking BOOST. Every active sits inside published human-tolerability data at or above the dose we use, and the formula is designed to stay inside established safe-intake levels. That said, no supplement is risk-free for everyone — see the ingredient table above for specific considerations, and speak to your GP or pharmacist first if you take prescription medication or have a diagnosed health condition.
Can I take BOOST with blood thinners?
Check with your GP or pharmacist first. Fenugreek, ginger, ginseng and forskolin can each have a mild effect on platelet function. Not necessarily a reason to avoid BOOST — but a reason to have a short conversation before starting.
Can I take BOOST with diabetes medication?
Check with your GP or pharmacist first. Fenugreek and ashwagandha can each mildly affect blood-sugar control.
Is BOOST safe to take long-term?
The ingredients and their doses sit within published human tolerability data; there is no specific reason to limit duration. Many customers take BOOST on an ongoing 12-month subscription without issue. As with any supplement, periodic review with your GP — especially during an annual check-up — is sensible.
Will BOOST affect my sleep?
Most men find BOOST neutral or beneficial for sleep — KSM-66 Ashwagandha is studied for stress and sleep quality. A small number of men are sensitive to mildly sedative ingredients; if you are, take BOOST in the evening with your meal (the recommended timing) rather than early in the day.
Can I take BOOST if I have a thyroid condition?
Speak to your GP first. Ashwagandha can affect thyroid hormone levels — in some people positively, in others it may require a prescription-dose adjustment.
Can I take BOOST before surgery?
Stop taking BOOST at least two weeks before planned surgery. Some herbal actives can mildly affect clotting. Tell your anaesthetist about every supplement you've been taking.
What should I do if I notice a side effect?
Pause BOOST and if symptoms persist speak to your GP or pharmacist. Email us at hello@himmense.com so we can log it. For serious symptoms (facial swelling, breathing difficulty, rapid rash, severe pain) stop immediately and seek urgent medical advice — as with any supplement, food or new routine.
Can my partner take BOOST?
BOOST is formulated for adult men. It is not formulated for women, and should not be taken during pregnancy or breastfeeding.
Still deciding?
For the full ingredient breakdown with every dose, see Himmense BOOST Ingredients UK. For the brand background, see Is Himmense Legit? 7-point check. For the full UK comparison, see Himmense BOOST vs the UK's Best-Selling Testosterone Supplements.
This article is general information, not medical advice, and not a substitute for a consultation with a qualified healthcare professional. Food supplements are not a substitute for a varied and balanced diet or healthy lifestyle. Do not exceed the recommended daily dose. If you are pregnant, breastfeeding, under 18, taking prescription medication, or have a medical condition, consult your GP or pharmacist before starting any new food supplement. KSM-66® is a trademark of Ixoreal Biomed. Testofen® is a registered trademark of Gencor. PrimaVie® is a trademark of Natreon. Tesnor® is a registered trademark of Laila Nutra and Gencor. ForsLean® and BioPerine® are trademarks of Sabinsa.
