Ashwagandha vs Iron Bisglycinate

Adaptogen vs Mineral · evidence-backed comparison

Quick take
  • Iron Bisglycinate has the stronger evidence base (strong (multiple rcts / meta-analyses)).
  • Ashwagandha has the broader effect profile across the 9 effect categories.
  • Iron Bisglycinate is cheaper per serving ($0.18 vs $0.30).
  • Ashwagandha has a slightly cleaner safety profile.
  • Iron Bisglycinate has higher bioavailability (better absorption).

Side-by-side traits

TraitAshwagandhaIron Bisglycinate
Category
AdaptogenMineral
Active compound
WithanolidesFerrous bisglycinate
Form available
Capsule, Powder, LiquidCapsule, Tablet
Source
plantsynthetic
Typical dose
300–600 mg (5% withanolides)18–25 mg elemental iron
Dose range
300–600 mg18–25 mg
Loading protocol
Best taken with
with foodvitamin C, empty stomach (or with food if GI sensitive)
Best time of day
anymorning
Bioavailability
How efficiently the body absorbs and utilizes the compound.
High (4/5)Very High (5/5)
Onset time
Cumulative: 4–8 weeksCumulative: 4–12 weeks
Half-life
~7 hours
Evidence level
Quality and quantity of human research.
Moderate (some RCTs)Strong (multiple RCTs / meta-analyses)
Overall effect
Subjective effect magnitude.
Moderate (3/5)Moderate (3/5)
Muscle / strength
Moderate (3/5)Low (2/5)
Physical energy
Moderate (3/5)High (4/5)
Focus / cognition
Moderate (3/5)Moderate (3/5)
Mood / stress
High (4/5)Moderate (3/5)
Sleep quality
High (4/5)Low (2/5)
Immunity
Moderate (3/5)Low (2/5)
Recovery
Post-exercise recovery support.
High (4/5)Moderate (3/5)
Longevity / healthspan
Moderate (3/5)Very Low (1/5)
Safety rating
5 = exceptionally well-tolerated; 1 = significant risk profile.
High (4/5)Moderate (3/5)
Price per serving
Approximate USD per typical daily dose.
$0.30$0.18
Vegan friendly
YesYes
Gluten free
YesYes
3rd-party tested
YesYes

About Ashwagandha

The most clinically-studied adaptogen. Reliably lowers cortisol, raises testosterone in stressed men, and improves sleep onset.

Active compound: Withanolides
Forms: Capsule, Powder, Liquid
Onset: Cumulative: 4–8 weeks
cortisoltestosteronestresssleep

About Iron Bisglycinate

Best-tolerated iron form for treating deficiency anemia. Don't supplement without a confirmed low ferritin / low Hgb test.

Active compound: Ferrous bisglycinate
Forms: Capsule, Tablet
Onset: Cumulative: 4–12 weeks
anemiaenergymenstruationendurance

Ashwagandha safety

Common side effects:

  • Mild GI upset
  • Drowsiness
  • Increased thyroid hormone

Avoid if:

  • Hyperthyroid
  • Pregnancy
  • Autoimmune disease (theoretical)

Drug interactions:

  • Thyroid meds
  • Sedatives
  • Immunosuppressants

Iron Bisglycinate safety

Common side effects:

  • Constipation (less than ferrous sulfate)
  • Dark stools

Avoid if:

  • Hemochromatosis
  • Iron overload
  • Untested males without deficiency

Drug interactions:

  • Levothyroxine
  • Calcium
  • PPIs

Common uses

  • Stress / anxiety
  • Sleep
  • Testosterone (in stressed men)
  • Strength

Stacks well with: Rhodiola Rosea, Magnesium Glycinate

Common uses

  • Anemia treatment
  • Heavy menstruation
  • Endurance athletes

Stacks well with: Vitamin C

Medical disclaimer

SupplementDuel is for educational purposes only and is not medical advice. Consult a physician before starting, stopping, or combining supplements — especially if you are pregnant, breastfeeding, take prescription medication, or have a chronic condition.