Huperzia Serrata is a firmross plant and is used to make the acetylcholinesterase inhibitor Huperzine A. Studies have shown it to have nootropic properties. It is commonly sold it the US as a dietary supplement for memory support.
What Is Huperzia Serrata?
Huperzia serrata is a natural nootropic that is native to India and southeast Asia. This extract has been used in China for centuries to treat a number of conditions including fever and inflammation. Researchers later discovered that this nootropic contained Huperzine-A, an alkaloid that easily crosses the blood brain barrier and acts as an AChE inhibitor. Today Huperzia is commonly distributed as an over-the-counter nootropic and dietary supplement.
How Does Huperzia Serrata Work?
Huperzia contains the alkaloid Huperzine-A. This alkaloid readily crosses the blood brain barrier to act as an AChE inhibitor. AChE also known as acetylcholinesterase is an enzyme that destroys the neurotransmitter acetylcholine. When AChE is inhibited levels of acetylcholine in the brain rise. 
Acetycholine the only neurotransmitter used in the motor division of the somatic nervous system. It activates muscles in the peripheral nervous system and plays a very important role in our ability to sustain attention in the central nervous system. It also has a variety of effects as a neuromodulator upon plasticity meaning it affects our short-term memory and our ability to learn.
Huperzine-A also acts as an NMDA receptor antagonist. This means it protects the brain against glutamate induced damage. 
Should I Use Huperzia Serrata?
Huperzia Serrata is a great nootropic. It is regarded as being very safe while greatly enhancing not only memory but also the rate at which you produce brain cells. Not to mention it is good for keeping your brain in good mental health and staving off Alzheimer’s disease. If you are trying to improve your memory and overall mental state through nootropics then this is a great one to consider for your regimen. The only downside is that you should discontinue use for a week every month.
Also, if you are currently using choline then this is an excellent nootropic to use for a synergetic effect. Choline increase the production of acetylcholine while Huperzia inhibits enzymes that destroy acetylcholine. When you combine both of these nootropics, their mechanisms of action work in unison to greatly increase choline levels beyond what either could do alone.
Huperzia Serrata Dosage Information
A dosage of 50-100 mcg is recommended for Huperzine-A. If you are buying dosages of Huperzia Serrata make sure you know what percentage of it is actually Huperzine-A. For example, the nootropic stack alpha brain contains 50mg of Huperzia Serrata at .5% Huperzine-A. This means it contains 25mcg of Huperzine-A. It is suggested to not exceed 200mcg of Huperzine-A daily.
Safety and Side Effects
Studies conducted in China have shown the Huperzine-A is not only just as effective as many other memory boosting smart drugs on the market but is safer in terms of side effects when taken at the correct dosage. 
Despite its safety possible side effects may include insomnia, skin reactions, upset stomach, and minor breathing problems.
Because Huperzine-A inhibits AChE one should not exceed the recommended dosages or use Huperzia for extended periods of time. Even though there are no reports of serious adverse reactions some scientists believe that blocking the natural regulation of acetylcholine for extended periods of time could cause your body to cease acetylcholine production. I would recommend taking a one week break every month just to be safe.
Huperzia Serrata Studies
One study conducted in 2005 aimed to study the effects of Huperzine-A on neutrinogenic activity and any effects it may have on the nerve growth factor. PC12 cells were observed under phase-contrast microscopy before and after being treated with Huperzine-A. Mitogenic activity, cell cytotoxicity, AChE activity, and mRNA expression were all measured. The study concluded that treatment of PC12 cells significantly increased the number of neurite-bearing cells, while causing no increase in any toxicity measure. There was an up-regulation of mRNA leading to an increase in the neuron growth factor. 
Another study conducted in 1999 aimed to determine if Huperzine-A capsules had an effect on the memory, learning, and performance of adolescent students. This study used a double-blind and matched pair method. Thirty four pairs of middle school students were divided into two groups based on different metrics. Half the students in each group were given a placebo while the others were given Huperzine-A. At the end of the trial, the students whom received the Huperzine-A had a significantly higher memory quotient (MQ) and scored significantly higher on various language tests. 
1. Wang, Bai-Song; Wang, Hao; Wei, Zhao-hui; Song, Yan-yan; Zhang, Lu; Chen, Hong-Zhuan (2009). “Efficacy and safety of natural acetylcholinesterase inhibitor huperzine A in the treatment of Alzheimer’s disease: an updated meta-analysis”. Journal of Neural Transmission 116 (4): 457.
2. Sun, QQ; Xu, SS; Pan, JL; Guo, HM; Cao, WQ (1999). “Huperzine-A capsules enhance memory and learning performance in 34 pairs of matched adolescent students.”. Zhongguo yao li xue bao = Acta pharmacologica Sinica 20 (7): 601–3. PMID 10678121.
3. Wang, BS; Wang, H; Wei, ZH; Song, YY; Zhang, L; Chen, HZ (2009). “Efficacy and safety of natural acetylcholinesterase inhibitor huperzine A in the treatment of Alzheimer’s disease: an updated meta-analysis.”. Journal of neural transmission (Vienna, Austria : 1996) 116 (4): 457–65. doi:10.1007/s00702-009-0189-x
4. Coleman, BR; Ratcliffe, RH; Oguntayo, SA; Shi, X; Doctor, BP; Gordon, RK; Nambiar, MP (2008). “+-Huperzine A treatment protects against N-methyl-D-aspartate-induced seizure/status epilepticus in rats.”. Chemico-biological interactions 175 (1-3): 387–95. doi:10.1016/j.cbi.2008.05.023. PMID 18588864.
5. Tang, L., Wang, R., Tang, X. (2005). “Effects of huperzine A on secretion of nerve growth factor in cultured rat cortical astrocytes and neurite outgrowth in rat PC12 cells”. Acta Pharmacologica Sinica 26 (6): 673–678. doi:10.1111/j.1745-7254.2005.00130.x. PMID 15916732.