Strengthera® - Clinical Research Data Summary
Strengthera® Mangifera indica & Sphaeranthus indicus Botanical Blend
Strengthera® is a clinically studied ingredient used in the following Silver Fern™ Brand product:
Introduction
Strengthera® is a clinically studied botanical blend designed to support lean muscle health, strength, endurance, and overall vitality. Formulated with standardized extracts of mango tree bark (Mangifera indica) and East Indian globe thistle (Sphaeranthus indicus), Strengthera® is designed to support key pathways involved in muscle protein synthesis, muscle recovery, healthy blood flow, and cellular energy production.*
Human clinical research suggests this botanical blend may help support improvements in measures of upper and lower body strength, grip strength, endurance, and physical performance when combined with regular exercise.*
These are the studies for Strengthera®. Below, we provided a summary of each key data for each study, along with a link to the complete clinical research.
- Summary of Study 1 – Full Study: https://pubmed.ncbi.nlm.nih.gov/41408545/
- Summary of Study 2 – Full Study: https://pubmed.ncbi.nlm.nih.gov/36794013/
- Summary of Study 3 – Full Study: https://pubmed.ncbi.nlm.nih.gov/38765822/
Ingredient Manufacturer Link: https://www.plthealth.com/product-catalog/strengthera
Study 1 Summary
Complete Study Information: https://pubmed.ncbi.nlm.nih.gov/41408545/
Effects of a 12-Week Calisthenics Program on Physical Performance, Strength, and Body Composition
Randomized controlled study.
This randomized controlled study evaluated the effects of a 12-week calisthenics (bodyweight exercise) program on body composition, muscular strength, cardiovascular endurance, and flexibility in adults with elevated body weight. This study provides foundational exercise science context relevant to Strengthera®'s clinical evidence base.
Study Design Highlights
- Study design: Randomized controlled study
- Intervention: 12-week structured calisthenics (bodyweight) program vs. control
- Assessment: Baseline and end of 12-week intervention
Key Findings (What the Study Showed)
After 12 weeks, the calisthenics group showed statistically significant improvements vs. control with large-to-moderate effect sizes:
- Flexibility (Sit-and-Reach): Effect size ~0.80 (large improvement)
- Cardiovascular Endurance (20m Shuttle Run): Effect size ~0.82 (large improvement)
- Right-Hand Grip Strength: Effect size ~0.75 (large improvement)
- Left-Hand Grip Strength: Effect size ~0.83 (large improvement)
- Back Muscle Strength: Effect size ~0.75 (large improvement)
- Leg Muscle Strength: Effect size ~0.54 (moderate improvement)
- Improvements in body composition including reductions in body weight and fat mass
Why This Study Matters for Strengthera®
Exercise provides the primary stimulus for muscular adaptation. This study demonstrates that even accessible, equipment-free exercise produces meaningful improvements in physical performance. Strengthera® is formulated with botanical extracts that have been clinically studied for their potential to further support muscle performance, recovery, and endurance when combined with regular training — helping individuals maximize the benefits of regular movement.*
Reference Link: https://pubmed.ncbi.nlm.nih.gov/41408545/
Study 2 Summary
Complete Study Information: https://pubmed.ncbi.nlm.nih.gov/36794013/
Randomized, Double-Blind, Placebo-Controlled Trial of LI12542F6 (Sphaeranthus indicus + Mangifera indica) and Muscular Performance in Resistance-Trained Men
Randomized, double-blind, placebo-controlled clinical trial.
This randomized, double-blind, placebo-controlled clinical trial evaluated 650 mg/day of LI12542F6 (a proprietary blend of Sphaeranthus indicus flower head and Mangifera indica bark extracts) vs. placebo in 40 resistance-trained men (ages 18–40) over 56 days (8 weeks). All participants followed a standardized resistance training program.
Study Design Highlights
- Study design: Randomized, double-blind, placebo-controlled
- Participants: 40 resistance-trained men (ages 18–40)
- Dose: 650 mg/day LI12542F6 vs. placebo
- Duration: 56 days (8 weeks)
- Exercise: Standardized resistance training program for all participants
Key Findings (What the Study Showed)
Strength
- Bench press strength: Mean increase of ~27.6 kg vs. ~5 kg placebo
- Leg press strength: Statistically significant increase vs. placebo (p < 0.0001)
- Grip strength: Significant bilateral improvement (p < 0.0006)
Endurance and Body Composition
- Muscular endurance: ~1.96-fold increase in cable pull-down repetitions
- Time to exhaustion: ~24.9% increase vs. ~10.3% placebo
- Lean body mass: Mean increase of ~1.44 kg
- Fat mass: Mean reduction of ~0.97 kg
- Mid-upper arm circumference: Significant increase
Hormone Markers and Safety
- Favorable changes in selected hormone markers including increased free testosterone and reduced cortisol levels relative to placebo
- No adverse events reported; clinical safety markers within normal ranges throughout
Benefits of Strengthera® Demonstrated by This Study
Based directly on the clinical outcomes, the Strengthera® botanical blend at 650 mg/day combined with resistance training was shown to:
✓ Support ~27.6 kg greater bench press strength increase vs. ~5 kg placebo
✓ Support statistically significant leg press and grip strength improvements
✓ Support ~1.96-fold increase in muscular endurance
✓ Support ~24.9% increase in time to exhaustion vs. ~10.3% placebo
✓ Support ~1.44 kg lean body mass increase and ~0.97 kg fat mass reduction
✓ Support favorable hormone marker changes (free testosterone, cortisol)
✓ Be well tolerated with no adverse events over 8 weeks
Why This Study Matters
This double-blind, placebo-controlled trial provides robust clinical evidence that the Strengthera® botanical blend, when combined with resistance training, may support substantially greater improvements in muscle strength, endurance, and body composition compared with exercise alone in healthy young men.*
Reference Link: https://pubmed.ncbi.nlm.nih.gov/36794013/
Study 3 Summary
Complete Study Information: https://pubmed.ncbi.nlm.nih.gov/38765822/
A Botanical Extract Blend of Mangifera indica and Sphaeranthus indicus Combined with Resistance Exercise Training Improves Muscle Strength and Endurance Over Exercise Alone in Young Men
Front Nutr. 2024 May 3;11:1393917. doi: 10.3389/fnut.2024.1393917.
This randomized, blinded, placebo-controlled trial evaluated a standardized SMI botanical blend (Sphaeranthus indicus flower head + Mangifera indica bark extracts) at 425 mg/day and 850 mg/day vs. placebo in 99 healthy men (mean age 22 ± 3 years) over 8 weeks. All participants performed resistance training 3x/week at ~80% 1-rep max (bench press and leg extension, 6–8 reps per set).
Study Design Highlights
- Study design: Randomized, blinded, placebo-controlled
- Participants: 99 healthy men (mean age 22 ± 3 years)
- Groups: 425 mg/day SMI + 1 training set; 850 mg/day SMI + 1 training set; Placebo + 1 training set; Placebo + 2 training sets
- Duration: 8 weeks; 3 resistance training sessions/week
Key Findings (What the Study Showed)
Upper Body Strength (Bench Press)
- 425 mg group: ~15% greater improvement vs. placebo (1 training set)
- 850 mg group: ~22–25% greater improvement vs. placebo (1 training set)
Lower Body Strength (Leg Extension)
- Supplemented groups: ~10–14% greater improvement vs. placebo (1 training set)
Muscular Endurance and Hormone Markers
- Participants receiving the botanical blend performed more repetitions to failure than those performing exercise alone
- Increases in total and free testosterone in supplemented groups
- Reduced cortisol levels in the higher-dose group vs. placebo
- No adverse events reported; clinical safety markers within normal ranges; well tolerated
Benefits of Strengthera® Demonstrated by This Study
Based directly on the clinical outcomes, the Strengthera® botanical blend at 425–850 mg/day combined with resistance training was shown to:
✓ Support ~15–25% greater bench press strength improvements vs. exercise alone
✓ Support ~10–14% greater leg extension strength improvements vs. exercise alone
✓ Support greater muscular endurance (more repetitions to failure)
✓ Support increases in total and free testosterone
✓ Support reduced cortisol in the higher-dose group
✓ Demonstrate dose-dependent effects (850 mg > 425 mg for bench press)
✓ Be well tolerated with no adverse events over 8 weeks
Why This Study Matters
This 99-participant trial is the largest in the Strengthera® evidence base and demonstrates consistent, dose-dependent improvements in strength and endurance with 1 training set + botanical blend vs. 1 training set alone — with the 850 mg dose producing strength improvements comparable to or exceeding those of the placebo group performing 2 training sets.*
Reference Link: https://pubmed.ncbi.nlm.nih.gov/38765822/
Big-Picture Integration with Other Studies
- Study 1: A 12-week randomized controlled calisthenics study demonstrating that structured bodyweight exercise produces large improvements in grip strength (ES ~0.75–0.83), cardiovascular endurance (ES ~0.82), and flexibility (ES ~0.80) — establishing the exercise science context for Strengthera®'s benefit claims.
- Study 2: An 8-week randomized, double-blind, placebo-controlled trial in 40 resistance-trained men showing that 650 mg/day of the Strengthera® botanical blend combined with resistance training was associated with ~27.6 kg greater bench press increase, ~1.96-fold endurance improvement, ~24.9% greater time to exhaustion, and ~1.44 kg lean mass gain vs. placebo — with favorable hormone markers and no adverse events.
- Study 3: An 8-week randomized, blinded, placebo-controlled trial in 99 healthy men showing 425–850 mg/day of the Strengthera® botanical blend combined with resistance training produced 15–25% greater bench press strength improvements and 10–14% greater leg extension improvements vs. exercise alone — with dose-dependent effects, greater muscular endurance, and favorable testosterone and cortisol changes.
Strengthera® Ingredient Summary & Real-World Relevance
Strengthera® is formulated around a clinically studied botanical blend of Mangifera indica (mango bark) and Sphaeranthus indicus (East Indian globe thistle) that has been evaluated in human clinical research for its potential to support muscle strength, endurance, and body composition when combined with regular exercise. Studies suggest that this botanical blend may help support improvements in physical performance measures, and in two randomized controlled trials, supplementation alongside training was associated with greater improvements in strength and endurance compared with exercise alone — while remaining well tolerated.*
In practical terms, this research highlights the potential role of targeted nutritional support in helping individuals maintain lean muscle, support physical performance, and maximize the benefits of regular movement and resistance training across a range of activity levels.*
Ingredient Manufacturer Link: https://www.plthealth.com/product-catalog/strengthera
Strengthera® is a clinically studied ingredient used in the following Silver Fern™ Brand product:
*These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.