Product Description
Training breaks your body down. Recovery builds it back up. But there's a third factor most athletes overlook: the daily physiological stress of hard training quietly depletes your B vitamins faster than your diet can replace them.
When those stores run low, energy production slows, mood tanks, and your cortisol response — the mechanism that helps you bounce back from hard efforts — becomes out of balance.
Thorne Stress B-Complex is built specifically for this gap.
Active Forms Your Body Can Actually Use – Most B-complex supplements deliver inactive vitamin forms that your body has to convert before they work. Thorne skips that step entirely, delivering all eight B vitamins in tissue-ready, active forms — including methylcobalamin B12 and methylated folate (5-MTHF) — so absorption is immediate and efficient.
Extra B5 to Support Your Stress Response – Pantothenic acid (vitamin B5) is the nutrient your adrenal glands rely on to regulate cortisol, the hormone that manages your body's response to training stress. Most B-complexes give you a token dose. Thorne includes 250mg per serving, the level needed to meaningfully support adrenal function under real training loads.
Complete Neuro and Energy Support in One Capsule – Choline is added alongside the eight core B vitamins to support neurotransmitter production, sharper focus, and mood stability — all the things that quietly degrade when training volume climbs and recovery falls short.
Every B vitamin in this formula works synergistically to support cellular energy production, red blood cell formation, and healthy nervous system function. B vitamins are water-soluble, meaning your body doesn't store them — daily replenishment is essential, especially when your training output is high.
How to Use Thorne Stress B-Complex
Daily Maintenance: Take 1 capsule daily with breakfast to support baseline energy metabolism and cortisol regulation throughout your training cycle.
High-Stress Periods: During peak training blocks or travel-heavy race seasons, take 1 capsule up to three times daily, split across meals, as recommended by your healthcare practitioner.
Pro Tip: Morning dosing with food is ideal — B vitamins are energizing by nature and may interfere with sleep if taken too late in the day.
- Gluten free
Supplement Facts
60 Servings
Serving Size: One Capsule
Serving Per Container: 60
| Amount Per Serving | ||
|---|---|---|
| % Daily Value* | ||
| Thiamin (as Thiamin HCl) 50mg | ** | |
| Riboflavin (25 mg as Riboflavin and 3.6 mg as Riboflavin 5'-Phosphate Sodium) 28.6mg | ** | |
| Niacin (as Niacinamide) 80mg | ** | |
| Vitamin B6 (25 mg as Pyridoxine HCl and 3.4 mg as Pyridoxal 5'-Phosphate) 28.4mg | ** | |
| Folate (200 mcg as L-5-Methyltetrahydrofolate from L-5-Methyltetrahydrofolic Acid, Glucosamine Salt) 334mcg DFE | ** | |
| Vitamin B12 (as Methylcobalamin) 100mcg | ** | |
| Biotin 80mcg | ** | |
| Pantothenic Acid (as Calcium Pantothenate) 250mg | ** | |
| Choline (as Choline Citrate) 14mg | ** | |
* Percent Daily Values are based on a 2,000 calorie diet. Your daily values may be higher or lower depending on your calorie needs.
** Daily Value (DV) not established
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Thorne Stress B-Complex FAQ's
Everything you need to know before getting started.



Take 1 capsule with breakfast. B vitamins support energy metabolism, so morning dosing primes your energy systems for the day. Avoid late-day dosing — the energizing effect can disrupt sleep in some athletes.
Most B-complexes use inactive vitamin forms that your body has to convert before they work. Thorne uses active, tissue-ready forms — including methylcobalamin B12 and 5-MTHF folate — for faster, more efficient absorption. It also includes 250mg of B5, significantly more than most formulas, to specifically support adrenal function under training stress.
Pantothenic acid is the vitamin your adrenal glands rely on to regulate cortisol — the hormone that governs your body's response to both physical and mental stress. When B5 stores run low, your stress response becomes less efficient, leading to fatigue, slower recovery, and mood disruption. Thorne includes a clinical-level dose to address this directly.
Yes, though be mindful of B vitamin overlap if your multivitamin already includes a full B-complex. In that case, consider taking just 1 capsule of Stress B-Complex daily rather than the full dose, or consult your practitioner to personalize your stack.